From e693cbb0a13c5c1e22661364cec602511abc03db Mon Sep 17 00:00:00 2001
From: Tim Pillinger <26465611+wxtim@users.noreply.github.com>
Date: Wed, 25 Nov 2020 11:58:56 +0000
Subject: [PATCH 1/7] move suite servers to scheduler section of global config

---
 cylc/flow/cfgspec/globalcfg.py        | 62 +++++++++++++--------------
 cylc/flow/host_select.py              |  6 +--
 cylc/flow/main_loop/auto_restart.py   | 16 +++----
 cylc/flow/scheduler.py                |  2 +-
 cylc/flow/scheduler_cli.py            |  2 +-
 tests/integration/conftest.py         |  2 +-
 tests/unit/network/test_publisher.py  |  2 +-
 tests/unit/test_host_select.py        | 10 ++---
 tests/unit/test_host_select_remote.py | 12 +++---
 9 files changed, 56 insertions(+), 58 deletions(-)

diff --git a/cylc/flow/cfgspec/globalcfg.py b/cylc/flow/cfgspec/globalcfg.py
index fe0940c0e90..11e8095b2ef 100644
--- a/cylc/flow/cfgspec/globalcfg.py
+++ b/cylc/flow/cfgspec/globalcfg.py
@@ -101,6 +101,36 @@
              desc='''
             The number of old run directory trees to retain at start-up.
         ''')
+        Conf('run hosts', VDR.V_SPACELESS_STRING_LIST, desc='''
+            A list of allowed suite run hosts. One of these hosts will be
+            appointed for a suite to start up on if an explicit host is not
+            provided as an option to a ``run`` or ``restart`` command.
+        ''')
+        Conf('run ports', VDR.V_INTEGER_LIST, list(range(43001, 43101)),
+             desc='''
+            A list of allowed ports for Cylc to use to run suites.
+        ''')
+        Conf('condemned hosts', VDR.V_ABSOLUTE_HOST_LIST, desc='''
+            Hosts specified in ``condemned hosts`` will not be considered as
+            suite run hosts. If suites are already running on ``condemned
+            hosts`` they will be automatically shutdown and restarted (see
+            :ref:`auto-stop-restart`).
+        ''')
+        Conf('auto restart delay', VDR.V_INTERVAL, desc='''
+            Relates to Cylc's auto stop-restart mechanism (see
+            :ref:`auto-stop-restart`).  When a host is set to automatically
+            shutdown/restart it will first wait a random period of time between
+            zero and ``auto restart delay`` seconds before beginning the
+            process. This is to prevent large numbers of suites from restarting
+            simultaneously.
+        ''')
+        Conf('ranking', VDR.V_STRING, desc='''
+            A multiline string containing Python expressions to filter
+            and/or rank hosts. For example:
+            cpu_percent() < 70
+            cpu_percent()
+            to filter by cpu_percent() < 70 then to rank by cpu_percent.
+        ''')
 
         with Conf('events', desc='''
             You can define site defaults for each of the following options,
@@ -579,38 +609,6 @@
             host if you have to use the *hardwired* self-identification method.
         ''')
 
-    # suite
-    with Conf('suite servers', desc='''
-        Configure allowed suite hosts and ports for starting up (running or
-        restarting) suites. Additionally configure host selection settings
-        specifying how to determine the most suitable run host at any given
-        time from those configured.
-    '''):
-        Conf('run hosts', VDR.V_SPACELESS_STRING_LIST, desc='''
-            A list of allowed suite run hosts. One of these hosts will be
-            appointed for a suite to start up on if an explicit host is not
-            provided as an option to a ``run`` or ``restart`` command.
-        ''')
-        Conf('run ports', VDR.V_INTEGER_LIST, list(range(43001, 43101)),
-             desc='''
-            A list of allowed ports for Cylc to use to run suites.
-        ''')
-        Conf('condemned hosts', VDR.V_ABSOLUTE_HOST_LIST, desc='''
-            Hosts specified in ``condemned hosts`` will not be considered as
-            suite run hosts. If suites are already running on ``condemned
-            hosts`` they will be automatically shutdown and restarted (see
-            :ref:`auto-stop-restart`).
-        ''')
-        Conf('auto restart delay', VDR.V_INTERVAL, desc='''
-            Relates to Cylc's auto stop-restart mechanism (see
-            :ref:`auto-stop-restart`).  When a host is set to automatically
-            shutdown/restart it will first wait a random period of time between
-            zero and ``auto restart delay`` seconds before beginning the
-            process. This is to prevent large numbers of suites from restarting
-            simultaneously.
-        ''')
-        Conf('ranking', VDR.V_STRING)
-
 
 def upg(cfg, descr):
     """Upgrader."""
diff --git a/cylc/flow/host_select.py b/cylc/flow/host_select.py
index 05de6d795dd..3215aa13e3d 100644
--- a/cylc/flow/host_select.py
+++ b/cylc/flow/host_select.py
@@ -61,12 +61,12 @@ def select_suite_host(cached=True):
 
     return select_host(
         # list of suite hosts
-        global_config.get(['suite servers', 'run hosts']) or ['localhost'],
+        global_config.get(['scheduler', 'run hosts']) or ['localhost'],
         # rankings to apply
-        ranking_string=global_config.get(['suite servers', 'ranking']),
+        ranking_string=global_config.get(['scheduler', 'ranking']),
         # list of condemned hosts
         blacklist=global_config.get(
-            ['suite servers', 'condemned hosts']
+            ['scheduler', 'condemned hosts']
         ),
         blacklist_name='condemned host'
     )
diff --git a/cylc/flow/main_loop/auto_restart.py b/cylc/flow/main_loop/auto_restart.py
index f8d035f3e51..de113101c06 100644
--- a/cylc/flow/main_loop/auto_restart.py
+++ b/cylc/flow/main_loop/auto_restart.py
@@ -16,7 +16,7 @@
 """Automatically restart suites if they are running on bad servers.
 
 Loads in the global configuration to check if the server a suite is running
-on is listed in :cylc:conf:`global.cylc[suite servers]condemned hosts`.
+on is listed in :cylc:conf:`global.cylc[scheduler]condemned hosts`.
 
 This is useful if a host needs to be taken off-line e.g. for scheduled
 maintenance.
@@ -26,11 +26,11 @@
 
 .. cylc-scope:: global.cylc
 
-- :cylc:conf:`[suite servers]auto restart delay`
-- :cylc:conf:`[suite servers]condemned hosts`
-- :cylc:conf:`[suite servers]run hosts`
+- :cylc:conf:`[scheduler]auto restart delay`
+- :cylc:conf:`[scheduler]condemned hosts`
+- :cylc:conf:`[scheduler]run hosts`
 
-.. cylc-scope:: global.cylc[suite servers]
+.. cylc-scope:: global.cylc[scheduler]
 
 The auto stop-restart feature has two modes:
 
@@ -56,7 +56,7 @@
 
 .. code-block:: cylc
 
-   [suite servers]
+   [scheduler]
        run hosts = pub
        condemned hosts = foo, bar!
 
@@ -107,7 +107,7 @@ async def auto_restart(scheduler, _):
         _set_auto_restart(
             scheduler,
             restart_delay=current_glbl_cfg.get(
-                ['suite servers', 'auto restart delay']
+                ['scheduler', 'auto restart delay']
             ),
             mode=mode
         )
@@ -117,7 +117,7 @@ def _should_auto_restart(scheduler, current_glbl_cfg):
     # check if suite host is condemned - if so auto restart
     if scheduler.stop_mode is None:
         for host in current_glbl_cfg.get(
-                ['suite servers', 'condemned hosts']
+                ['scheduler', 'condemned hosts']
         ):
             if host.endswith('!'):
                 # host ends in an `!` -> force shutdown mode
diff --git a/cylc/flow/scheduler.py b/cylc/flow/scheduler.py
index b6ccc474bda..7d250c005c1 100644
--- a/cylc/flow/scheduler.py
+++ b/cylc/flow/scheduler.py
@@ -528,7 +528,7 @@ async def configure(self):
 
     async def start_servers(self):
         """Start the TCP servers."""
-        port_range = glbl_cfg().get(['suite servers', 'run ports'])
+        port_range = glbl_cfg().get(['scheduler', 'run ports'])
         self.server.start(port_range[0], port_range[-1])
         self.publisher.start(port_range[0], port_range[-1])
         # wait for threads to setup socket ports before continuing
diff --git a/cylc/flow/scheduler_cli.py b/cylc/flow/scheduler_cli.py
index 824040ccdd4..fbfa04bf584 100644
--- a/cylc/flow/scheduler_cli.py
+++ b/cylc/flow/scheduler_cli.py
@@ -207,7 +207,7 @@ def get_option_parser(is_restart, add_std_opts=False):
         help=(
             "Specify the host on which to start-up the suite. "
             "If not specified, a host will be selected using "
-            "the 'suite servers' global config."
+            "the '[scheduler]run hosts' global config."
         ),
         metavar="HOST", action="store", dest="host")
 
diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
index 1c83fd7060e..9c4f01f9881 100644
--- a/tests/integration/conftest.py
+++ b/tests/integration/conftest.py
@@ -213,7 +213,7 @@ def _log_filter(log, name=None, level=None, contains=None, regex=None):
 
 @pytest.fixture(scope='session')
 def port_range():
-    ports = glbl_cfg().get(['suite servers', 'run ports'])
+    ports = glbl_cfg().get(['scheduler', 'run ports'])
     return min(ports), max(ports)
 
 
diff --git a/tests/unit/network/test_publisher.py b/tests/unit/network/test_publisher.py
index 5df91ec1047..ab6063ad470 100644
--- a/tests/unit/network/test_publisher.py
+++ b/tests/unit/network/test_publisher.py
@@ -24,7 +24,7 @@
 
 @pytest.fixture(scope='session')
 def port_range():
-    ports = glbl_cfg().get(['suite servers', 'run ports'])
+    ports = glbl_cfg().get(['scheduler', 'run ports'])
     return min(ports), max(ports)
 
 
diff --git a/tests/unit/test_host_select.py b/tests/unit/test_host_select.py
index 0afcd1f6fb7..26e8b00c9ad 100644
--- a/tests/unit/test_host_select.py
+++ b/tests/unit/test_host_select.py
@@ -138,7 +138,7 @@ def test_suite_host_select(mock_glbl_cfg):
     mock_glbl_cfg(
         'cylc.flow.host_select.glbl_cfg',
         f'''
-            [suite servers]
+            [scheduler]
                 run hosts = {localhost}
         '''
     )
@@ -150,7 +150,7 @@ def test_suite_host_select_default(mock_glbl_cfg):
     mock_glbl_cfg(
         'cylc.flow.host_select.glbl_cfg',
         '''
-            [suite servers]
+            [scheduler]
                 run hosts =
         '''
     )
@@ -169,7 +169,7 @@ def test_suite_host_select_condemned(mock_glbl_cfg):
     mock_glbl_cfg(
         'cylc.flow.host_select.glbl_cfg',
         f'''
-            [suite servers]
+            [scheduler]
                 run hosts = {localhost}
                 condemned hosts = {localhost_fqdn}
         '''
@@ -181,7 +181,7 @@ def test_suite_host_select_condemned(mock_glbl_cfg):
 
 
 def test_condemned_host_ambiguous(mock_glbl_cfg):
-    """Test the [suite servers]condemend host coercer
+    """Test the [scheduler]condemend host coercer
 
     Not actually host_select code but related functionality.
     """
@@ -189,7 +189,7 @@ def test_condemned_host_ambiguous(mock_glbl_cfg):
         mock_glbl_cfg(
             'cylc.flow.host_select.glbl_cfg',
             f'''
-                [suite servers]
+                [scheduler]
                     run hosts = {localhost}
                     condemned hosts = {localhost}
             '''
diff --git a/tests/unit/test_host_select_remote.py b/tests/unit/test_host_select_remote.py
index ebd95fdf621..2a3820bd44b 100644
--- a/tests/unit/test_host_select_remote.py
+++ b/tests/unit/test_host_select_remote.py
@@ -130,11 +130,11 @@ def mocked_get_metrics(hosts, metrics, _=None):
 
 
 def test_remote_suite_host_select(mock_glbl_cfg):
-    """test [suite servers]run hosts"""
+    """test [scheduler]run hosts"""
     mock_glbl_cfg(
         'cylc.flow.host_select.glbl_cfg',
         f'''
-            [suite servers]
+            [scheduler]
                 run hosts = {remote_platform}
         '''
     )
@@ -142,11 +142,11 @@ def test_remote_suite_host_select(mock_glbl_cfg):
 
 
 def test_remote_suite_host_condemned(mock_glbl_cfg):
-    """test [suite servers]condemned hosts"""
+    """test [scheduler]condemned hosts"""
     mock_glbl_cfg(
         'cylc.flow.host_select.glbl_cfg',
         f'''
-            [suite servers]
+            [scheduler]
                 run hosts = {remote_platform}, {local_host}
                 condemned hosts = {remote_platform}
         '''
@@ -156,11 +156,11 @@ def test_remote_suite_host_condemned(mock_glbl_cfg):
 
 
 def test_remote_suite_host_rankings(mock_glbl_cfg):
-    """test [suite servers]rankings"""
+    """test [scheduler]rankings"""
     mock_glbl_cfg(
         'cylc.flow.host_select.glbl_cfg',
         f'''
-            [suite servers]
+            [scheduler]
                 run hosts = {remote_platform}
                 ranking = """
                     # if this test fails due to race conditions

From 40b9dae34a8e7a1c76cd26f9a2450ba70468948d Mon Sep 17 00:00:00 2001
From: Tim Pillinger <26465611+wxtim@users.noreply.github.com>
Date: Wed, 25 Nov 2020 16:17:57 +0000
Subject: [PATCH 2/7] fixed 2 flakyfunctional tests I'd missed

---
 .../restart/39-auto-restart-no-suitable-host.t                | 4 ++--
 tests/flakyfunctional/restart/40-auto-restart-force-stop.t    | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/flakyfunctional/restart/39-auto-restart-no-suitable-host.t b/tests/flakyfunctional/restart/39-auto-restart-no-suitable-host.t
index cabe1b5f238..84dd77d50e0 100644
--- a/tests/flakyfunctional/restart/39-auto-restart-no-suitable-host.t
+++ b/tests/flakyfunctional/restart/39-auto-restart-no-suitable-host.t
@@ -44,7 +44,7 @@ init_suite "${TEST_NAME_BASE}" <<< '
 
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
+[scheduler]
     run hosts = localhost
 "
 
@@ -53,7 +53,7 @@ poll_suite_running
 
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
+[scheduler]
     run hosts = localhost
     condemned hosts = $(localhost_fqdn)
 "
diff --git a/tests/flakyfunctional/restart/40-auto-restart-force-stop.t b/tests/flakyfunctional/restart/40-auto-restart-force-stop.t
index aa9968d28d0..2f93c8617db 100644
--- a/tests/flakyfunctional/restart/40-auto-restart-force-stop.t
+++ b/tests/flakyfunctional/restart/40-auto-restart-force-stop.t
@@ -40,7 +40,7 @@ init_suite "${TEST_NAME_BASE}" <<< '
 
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
+[scheduler]
     run hosts = localhost
 "
 
@@ -49,7 +49,7 @@ poll_suite_running
 
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
+[scheduler]
     run hosts = localhost
     condemned hosts = $(localhost_fqdn)!
 "

From 3235d53e4601e6ec4bb9a90d377b28aace652ca7 Mon Sep 17 00:00:00 2001
From: Tim Pillinger <26465611+wxtim@users.noreply.github.com>
Date: Thu, 26 Nov 2020 10:25:29 +0000
Subject: [PATCH 3/7] Moved [suite servers] items to [scheduler][run hosts]

---
 cylc/flow/cfgspec/globalcfg.py                | 67 ++++++++++---------
 cylc/flow/host_select.py                      | 10 ++-
 cylc/flow/main_loop/auto_restart.py           |  2 +-
 cylc/flow/scheduler.py                        |  2 +-
 .../39-auto-restart-no-suitable-host.t        |  8 ++-
 .../restart/40-auto-restart-force-stop.t      |  8 ++-
 .../restart/34-auto-restart-basic.t           | 10 +--
 .../restart/35-auto-restart-recovery.t        | 10 +--
 .../restart/37-auto-restart-delay.t           | 16 +++--
 .../restart/38-auto-restart-stopping.t        |  9 +--
 .../restart/41-auto-restart-local-jobs.t      | 19 +++---
 .../restart/42-auto-restart-ping-pong.t       |  7 +-
 .../43-auto-restart-force-override-normal.t   | 19 +++---
 tests/integration/conftest.py                 |  2 +-
 tests/unit/network/test_publisher.py          |  2 +-
 tests/unit/test_host_select.py                | 16 +++--
 tests/unit/test_host_select_remote.py         | 31 +++++----
 17 files changed, 137 insertions(+), 101 deletions(-)

diff --git a/cylc/flow/cfgspec/globalcfg.py b/cylc/flow/cfgspec/globalcfg.py
index 11e8095b2ef..c5bd54b36f1 100644
--- a/cylc/flow/cfgspec/globalcfg.py
+++ b/cylc/flow/cfgspec/globalcfg.py
@@ -101,36 +101,43 @@
              desc='''
             The number of old run directory trees to retain at start-up.
         ''')
-        Conf('run hosts', VDR.V_SPACELESS_STRING_LIST, desc='''
-            A list of allowed suite run hosts. One of these hosts will be
-            appointed for a suite to start up on if an explicit host is not
-            provided as an option to a ``run`` or ``restart`` command.
-        ''')
-        Conf('run ports', VDR.V_INTEGER_LIST, list(range(43001, 43101)),
-             desc='''
-            A list of allowed ports for Cylc to use to run suites.
-        ''')
-        Conf('condemned hosts', VDR.V_ABSOLUTE_HOST_LIST, desc='''
-            Hosts specified in ``condemned hosts`` will not be considered as
-            suite run hosts. If suites are already running on ``condemned
-            hosts`` they will be automatically shutdown and restarted (see
-            :ref:`auto-stop-restart`).
-        ''')
-        Conf('auto restart delay', VDR.V_INTERVAL, desc='''
-            Relates to Cylc's auto stop-restart mechanism (see
-            :ref:`auto-stop-restart`).  When a host is set to automatically
-            shutdown/restart it will first wait a random period of time between
-            zero and ``auto restart delay`` seconds before beginning the
-            process. This is to prevent large numbers of suites from restarting
-            simultaneously.
-        ''')
-        Conf('ranking', VDR.V_STRING, desc='''
-            A multiline string containing Python expressions to filter
-            and/or rank hosts. For example:
-            cpu_percent() < 70
-            cpu_percent()
-            to filter by cpu_percent() < 70 then to rank by cpu_percent.
-        ''')
+        with Conf('run hosts', desc='''
+        Configure allowed suite hosts and ports for starting up (running or
+        restarting) suites. Additionally configure host selection settings
+        specifying how to determine the most suitable run host at any given
+        time from those configured.
+    '''):
+            Conf('available', VDR.V_SPACELESS_STRING_LIST, desc='''
+                A list of allowed suite run hosts. One of these hosts will be
+                appointed for a suite to start up on if an explicit host is not
+                provided as an option to a ``run`` or ``restart`` command.
+            ''')
+            Conf(
+                'ports', VDR.V_INTEGER_LIST, list(range(43001, 43101)),
+                desc='''
+                    A list of allowed ports for Cylc to use to run suites.
+            ''')
+            Conf('condemned', VDR.V_ABSOLUTE_HOST_LIST, desc='''
+                Hosts specified in ``condemned hosts`` will not be considered
+                as suite run hosts. If suites are already running on
+                ``condemned hosts`` they will be automatically shutdown and
+                restarted (see:ref:`auto-stop-restart`).
+            ''')
+            Conf('auto restart delay', VDR.V_INTERVAL, desc='''
+                Relates to Cylc's auto stop-restart mechanism (see
+                :ref:`auto-stop-restart`).  When a host is set to automatically
+                shutdown/restart it will first wait a random period of time
+                between zero and ``auto restart delay`` seconds before
+                beginning the process. This is to prevent large numbers of
+                suites from restarting simultaneously.
+            ''')
+            Conf('ranking', VDR.V_STRING, desc='''
+                A multiline string containing Python expressions to filter
+                and/or rank hosts. For example:
+                cpu_percent() < 70
+                cpu_percent()
+                to filter by cpu_percent() < 70 then to rank by cpu_percent.
+            ''')
 
         with Conf('events', desc='''
             You can define site defaults for each of the following options,
diff --git a/cylc/flow/host_select.py b/cylc/flow/host_select.py
index 3215aa13e3d..a290833b634 100644
--- a/cylc/flow/host_select.py
+++ b/cylc/flow/host_select.py
@@ -61,12 +61,16 @@ def select_suite_host(cached=True):
 
     return select_host(
         # list of suite hosts
-        global_config.get(['scheduler', 'run hosts']) or ['localhost'],
+        global_config.get([
+            'scheduler', 'run hosts', 'available'
+        ]) or ['localhost'],
         # rankings to apply
-        ranking_string=global_config.get(['scheduler', 'ranking']),
+        ranking_string=global_config.get([
+            'scheduler', 'run hosts', 'ranking'
+        ]),
         # list of condemned hosts
         blacklist=global_config.get(
-            ['scheduler', 'condemned hosts']
+            ['scheduler', 'run hosts', 'condemned']
         ),
         blacklist_name='condemned host'
     )
diff --git a/cylc/flow/main_loop/auto_restart.py b/cylc/flow/main_loop/auto_restart.py
index de113101c06..811f5bab99e 100644
--- a/cylc/flow/main_loop/auto_restart.py
+++ b/cylc/flow/main_loop/auto_restart.py
@@ -117,7 +117,7 @@ def _should_auto_restart(scheduler, current_glbl_cfg):
     # check if suite host is condemned - if so auto restart
     if scheduler.stop_mode is None:
         for host in current_glbl_cfg.get(
-                ['scheduler', 'condemned hosts']
+                ['scheduler', 'run hosts', 'condemned']
         ):
             if host.endswith('!'):
                 # host ends in an `!` -> force shutdown mode
diff --git a/cylc/flow/scheduler.py b/cylc/flow/scheduler.py
index 7d250c005c1..20feb21ce2c 100644
--- a/cylc/flow/scheduler.py
+++ b/cylc/flow/scheduler.py
@@ -528,7 +528,7 @@ async def configure(self):
 
     async def start_servers(self):
         """Start the TCP servers."""
-        port_range = glbl_cfg().get(['scheduler', 'run ports'])
+        port_range = glbl_cfg().get(['scheduler', 'run hosts', 'ports'])
         self.server.start(port_range[0], port_range[-1])
         self.publisher.start(port_range[0], port_range[-1])
         # wait for threads to setup socket ports before continuing
diff --git a/tests/flakyfunctional/restart/39-auto-restart-no-suitable-host.t b/tests/flakyfunctional/restart/39-auto-restart-no-suitable-host.t
index 84dd77d50e0..c9692326ad2 100644
--- a/tests/flakyfunctional/restart/39-auto-restart-no-suitable-host.t
+++ b/tests/flakyfunctional/restart/39-auto-restart-no-suitable-host.t
@@ -45,7 +45,8 @@ init_suite "${TEST_NAME_BASE}" <<< '
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
 [scheduler]
-    run hosts = localhost
+    [[run hosts]]
+        available = localhost
 "
 
 cylc run "${SUITE_NAME}" --debug
@@ -54,8 +55,9 @@ poll_suite_running
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
 [scheduler]
-    run hosts = localhost
-    condemned hosts = $(localhost_fqdn)
+    [[run hosts]]
+        available = localhost
+        condemned = $(localhost_fqdn)
 "
 
 FILE=$(cylc cat-log "${SUITE_NAME}" -m p |xargs readlink -f)
diff --git a/tests/flakyfunctional/restart/40-auto-restart-force-stop.t b/tests/flakyfunctional/restart/40-auto-restart-force-stop.t
index 2f93c8617db..ac32fc70cd0 100644
--- a/tests/flakyfunctional/restart/40-auto-restart-force-stop.t
+++ b/tests/flakyfunctional/restart/40-auto-restart-force-stop.t
@@ -41,7 +41,8 @@ init_suite "${TEST_NAME_BASE}" <<< '
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
 [scheduler]
-    run hosts = localhost
+    [[run hosts]]
+        available = localhost
 "
 
 cylc run "${SUITE_NAME}" --hold
@@ -50,8 +51,9 @@ poll_suite_running
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
 [scheduler]
-    run hosts = localhost
-    condemned hosts = $(localhost_fqdn)!
+    [[run hosts]]
+        available = localhost
+        condemned = $(localhost_fqdn)!
 "
 
 FILE=$(cylc cat-log "${SUITE_NAME}" -m p |xargs readlink -f)
diff --git a/tests/functional/restart/34-auto-restart-basic.t b/tests/functional/restart/34-auto-restart-basic.t
index f9663e80a70..f90e0616daa 100644
--- a/tests/functional/restart/34-auto-restart-basic.t
+++ b/tests/functional/restart/34-auto-restart-basic.t
@@ -33,8 +33,9 @@ BASE_GLOBAL_CONFIG="
         abort on timeout = True
         inactivity = PT1M
         timeout = PT1M
-[suite servers]
-    run hosts = localhost, ${CYLC_TEST_HOST}"
+[scheduler]
+    [[run hosts]]
+        available = localhost, ${CYLC_TEST_HOST}"
 
 TEST_NAME="${TEST_NAME_BASE}"
 TEST_DIR="$HOME/cylc-run/" init_suite "${TEST_NAME}" - <<'__FLOW_CONFIG__'
@@ -55,8 +56,9 @@ cylc suite-state "${SUITE_NAME}" --task='task_foo01' \
 # condemn localhost
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    condemned hosts = $(hostname)
+[scheduler]
+    [[run hosts]]
+        condemned = $(hostname)
 "
 # test shutdown procedure - scan the first log file
 FILE=$(cylc cat-log "${SUITE_NAME}" -m p |xargs readlink -f)
diff --git a/tests/functional/restart/35-auto-restart-recovery.t b/tests/functional/restart/35-auto-restart-recovery.t
index 51962953796..ea609228b9e 100644
--- a/tests/functional/restart/35-auto-restart-recovery.t
+++ b/tests/functional/restart/35-auto-restart-recovery.t
@@ -31,8 +31,9 @@ BASE_GLOBAL_CONFIG="
         abort on timeout = True
         inactivity = PT2M
         timeout = PT2M
-[suite servers]
-    run hosts = localhost, ${CYLC_TEST_HOST}"
+[scheduler]
+    [[run hosts]]
+        available = localhost, ${CYLC_TEST_HOST}"
 
 TEST_NAME="${TEST_NAME_BASE}"
 TEST_DIR="$HOME/cylc-run/" init_suite "${TEST_NAME}" <<< '
@@ -51,8 +52,9 @@ rm "${SUITE_RUN_DIR}/flow.cylc"
 # condemn localhost
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    condemned hosts = $(hostname)
+[scheduler]
+    [[run hosts]]
+        condemned = $(hostname)
 "
 
 FILE=$(cylc cat-log "${SUITE_NAME}" -m p |xargs readlink -f)
diff --git a/tests/functional/restart/37-auto-restart-delay.t b/tests/functional/restart/37-auto-restart-delay.t
index 7c57359190e..e3bd0b65571 100644
--- a/tests/functional/restart/37-auto-restart-delay.t
+++ b/tests/functional/restart/37-auto-restart-delay.t
@@ -53,9 +53,10 @@ TEST_DIR="$HOME/cylc-run/" init_suite "${TEST_NAME_BASE}" <<< '
 MAX_RESTART_DELAY=30
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    run hosts = localhost
-    auto restart delay = PT${MAX_RESTART_DELAY}S
+[scheduler]
+    [[run hosts]]
+        available = localhost
+        auto restart delay = PT${MAX_RESTART_DELAY}S
 "
 
 # Run suite.
@@ -65,10 +66,11 @@ poll_suite_running
 # Condemn host - trigger stop-restart.
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    run hosts = ${CYLC_TEST_HOST}
-    condemned hosts = $(hostname)
-    auto restart delay = PT20S
+[scheduler]
+    [[run hosts]]
+        available = ${CYLC_TEST_HOST}
+        condemned = $(hostname)
+        auto restart delay = PT20S
 "
 
 # Check stop-restart working.
diff --git a/tests/functional/restart/38-auto-restart-stopping.t b/tests/functional/restart/38-auto-restart-stopping.t
index feac867388a..04123cff984 100644
--- a/tests/functional/restart/38-auto-restart-stopping.t
+++ b/tests/functional/restart/38-auto-restart-stopping.t
@@ -32,8 +32,8 @@ BASE_GLOBAL_CONFIG="
         abort on timeout = True
         inactivity = PT1M
         timeout = PT1M
-[suite servers]
-    run hosts = localhost, ${CYLC_TEST_HOST}"
+    [[run hosts]]
+        available = localhost, ${CYLC_TEST_HOST}"
 
 TEST_NAME="${TEST_NAME_BASE}"
 
@@ -57,8 +57,9 @@ cylc suite-state "${SUITE_NAME}" --task='foo' --status='running' --point=1 \
 # condemn localhost
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    condemned hosts = $(hostname)
+[scheduler]
+    [[run hosts]]
+        condemned = $(hostname)
 "
 
 # wait for suite to die of natural causes
diff --git a/tests/functional/restart/41-auto-restart-local-jobs.t b/tests/functional/restart/41-auto-restart-local-jobs.t
index a8967357ffd..77d106e067a 100644
--- a/tests/functional/restart/41-auto-restart-local-jobs.t
+++ b/tests/functional/restart/41-auto-restart-local-jobs.t
@@ -49,8 +49,9 @@ TEST_DIR="$HOME/cylc-run/" init_suite "${TEST_NAME_BASE}" <<< '
 
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    run hosts = ${CYLC_TEST_HOST1}
+[scheduler]
+    [[run hosts]]
+        available = ${CYLC_TEST_HOST1}
 "
 
 cylc run "${SUITE_NAME}"
@@ -64,9 +65,10 @@ cylc suite-state "${SUITE_NAME}" --task='foo' --status='running' --point=1 \
 
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    run hosts = ${CYLC_TEST_HOST1}, ${CYLC_TEST_HOST2}
-    condemned hosts = ${CYLC_TEST_HOST1}
+[scheduler]
+    [[run hosts]]
+        available = ${CYLC_TEST_HOST1}, ${CYLC_TEST_HOST2}
+        condemned = ${CYLC_TEST_HOST1}
 "
 
 FILE="$(cylc cat-log "${SUITE_NAME}" -m p |xargs readlink -f)"
@@ -94,9 +96,10 @@ cylc suite-state "${SUITE_NAME}" --task='bar' --status='running' --point=1 \
 
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    run hosts = ${CYLC_TEST_HOST1}, ${CYLC_TEST_HOST2}
-    condemned hosts = ${CYLC_TEST_HOST2}!
+[scheduler]
+    [[run hosts]]
+        available = ${CYLC_TEST_HOST1}, ${CYLC_TEST_HOST2}
+        condemned = ${CYLC_TEST_HOST2}!
 "
 
 FILE="$(cylc cat-log "${SUITE_NAME}" -m p |xargs readlink -f)"
diff --git a/tests/functional/restart/42-auto-restart-ping-pong.t b/tests/functional/restart/42-auto-restart-ping-pong.t
index bc3492d729a..8f75739dd58 100644
--- a/tests/functional/restart/42-auto-restart-ping-pong.t
+++ b/tests/functional/restart/42-auto-restart-ping-pong.t
@@ -52,9 +52,10 @@ stuck_in_the_middle() {
     JOKERS="${CLOWNS}"; CLOWNS="${temp}"
     create_test_global_config '' "
     ${BASE_GLOBAL_CONFIG}
-    [suite servers]
-        run hosts = ${JOKERS}, ${CLOWNS}
-        condemned hosts = ${CLOWNS}
+    [scheduling]
+        [[run hosts]]
+            available = ${JOKERS}, ${CLOWNS}
+            condemned = ${CLOWNS}
     "
 }
 
diff --git a/tests/functional/restart/43-auto-restart-force-override-normal.t b/tests/functional/restart/43-auto-restart-force-override-normal.t
index 969fe68e066..4299e245075 100644
--- a/tests/functional/restart/43-auto-restart-force-override-normal.t
+++ b/tests/functional/restart/43-auto-restart-force-override-normal.t
@@ -46,8 +46,9 @@ TEST_DIR="$HOME/cylc-run/" init_suite "${TEST_NAME_BASE}" <<< '
 
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    run hosts = ${CYLC_TEST_HOST_1}
+[scheduler]
+    [[run hosts]]
+        available = ${CYLC_TEST_HOST_1}
 "
 
 set_test_number 7
@@ -61,10 +62,11 @@ FILE=$(cylc cat-log "${SUITE_NAME}" -m p |xargs readlink -f)
 # condemn the host, the suite will schedule restart in PT60S
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    run hosts = ${CYLC_TEST_HOST_1}, ${CYLC_TEST_HOST_2}
-    condemned hosts = ${CYLC_TEST_HOST_1}
-    auto restart delay = -PT60S  # results in +PT60S delay
+[scheduler]
+    [[run hosts]]
+        available = ${CYLC_TEST_HOST_1}, ${CYLC_TEST_HOST_2}
+        condemned = ${CYLC_TEST_HOST_1}
+        auto restart delay = -PT60S  # results in +PT60S delay
 "
 log_scan "${TEST_NAME_BASE}-stop" "${FILE}" 40 1 \
     'The Cylc suite host will soon become un-available' \
@@ -73,8 +75,9 @@ log_scan "${TEST_NAME_BASE}-stop" "${FILE}" 40 1 \
 # condemn the host in "Force Mode", this should cancel the scheduled restart
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
-[suite servers]
-    condemned hosts = ${CYLC_TEST_HOST_1}!
+[scheduler]
+    [[run hosts]]
+        condemned hosts = ${CYLC_TEST_HOST_1}!
 "
 log_scan "${TEST_NAME_BASE}-stop" "${FILE}" 40 1 \
     'This suite will be shutdown as the suite host is' \
diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
index 9c4f01f9881..d8d7de88d45 100644
--- a/tests/integration/conftest.py
+++ b/tests/integration/conftest.py
@@ -213,7 +213,7 @@ def _log_filter(log, name=None, level=None, contains=None, regex=None):
 
 @pytest.fixture(scope='session')
 def port_range():
-    ports = glbl_cfg().get(['scheduler', 'run ports'])
+    ports = glbl_cfg().get(['scheduler', 'run hosts', 'ports'])
     return min(ports), max(ports)
 
 
diff --git a/tests/unit/network/test_publisher.py b/tests/unit/network/test_publisher.py
index ab6063ad470..c3533a10a15 100644
--- a/tests/unit/network/test_publisher.py
+++ b/tests/unit/network/test_publisher.py
@@ -24,7 +24,7 @@
 
 @pytest.fixture(scope='session')
 def port_range():
-    ports = glbl_cfg().get(['scheduler', 'run ports'])
+    ports = glbl_cfg().get(['scheduler', 'run hosts', 'ports'])
     return min(ports), max(ports)
 
 
diff --git a/tests/unit/test_host_select.py b/tests/unit/test_host_select.py
index 26e8b00c9ad..917515d1216 100644
--- a/tests/unit/test_host_select.py
+++ b/tests/unit/test_host_select.py
@@ -139,7 +139,8 @@ def test_suite_host_select(mock_glbl_cfg):
         'cylc.flow.host_select.glbl_cfg',
         f'''
             [scheduler]
-                run hosts = {localhost}
+                [[run hosts]]
+                    available= {localhost}
         '''
     )
     assert select_suite_host() == (localhost, localhost_fqdn)
@@ -151,7 +152,8 @@ def test_suite_host_select_default(mock_glbl_cfg):
         'cylc.flow.host_select.glbl_cfg',
         '''
             [scheduler]
-                run hosts =
+                [[run hosts]]
+                    available =
         '''
     )
     hostname, host_fqdn = select_suite_host()
@@ -170,8 +172,9 @@ def test_suite_host_select_condemned(mock_glbl_cfg):
         'cylc.flow.host_select.glbl_cfg',
         f'''
             [scheduler]
-                run hosts = {localhost}
-                condemned hosts = {localhost_fqdn}
+                [[run hosts]]
+                    available = {localhost}
+                    condemned = {localhost_fqdn}
         '''
     )
     with pytest.raises(HostSelectException) as excinfo:
@@ -190,8 +193,9 @@ def test_condemned_host_ambiguous(mock_glbl_cfg):
             'cylc.flow.host_select.glbl_cfg',
             f'''
                 [scheduler]
-                    run hosts = {localhost}
-                    condemned hosts = {localhost}
+                    [[run hosts]]
+                        available = {localhost}
+                        condemned = {localhost}
             '''
         )
     assert 'ambiguous host' in excinfo.value.msg
diff --git a/tests/unit/test_host_select_remote.py b/tests/unit/test_host_select_remote.py
index 2a3820bd44b..36ee3772c95 100644
--- a/tests/unit/test_host_select_remote.py
+++ b/tests/unit/test_host_select_remote.py
@@ -130,25 +130,27 @@ def mocked_get_metrics(hosts, metrics, _=None):
 
 
 def test_remote_suite_host_select(mock_glbl_cfg):
-    """test [scheduler]run hosts"""
+    """test [scheduler][run hosts]available"""
     mock_glbl_cfg(
         'cylc.flow.host_select.glbl_cfg',
         f'''
             [scheduler]
-                run hosts = {remote_platform}
+                [[run hosts]]
+                    available = {remote_platform}
         '''
     )
     assert select_suite_host() == (remote_platform, remote_platform_fqdn)
 
 
 def test_remote_suite_host_condemned(mock_glbl_cfg):
-    """test [scheduler]condemned hosts"""
+    """test [scheduler][run hosts]condemned hosts"""
     mock_glbl_cfg(
         'cylc.flow.host_select.glbl_cfg',
         f'''
             [scheduler]
-                run hosts = {remote_platform}, {local_host}
-                condemned hosts = {remote_platform}
+                [[run hosts]]
+                    available = {remote_platform}, {local_host}
+                    condemned = {remote_platform}
         '''
     )
     for _ in range(10):
@@ -156,19 +158,20 @@ def test_remote_suite_host_condemned(mock_glbl_cfg):
 
 
 def test_remote_suite_host_rankings(mock_glbl_cfg):
-    """test [scheduler]rankings"""
+    """test [scheduler][run hosts]rankings"""
     mock_glbl_cfg(
         'cylc.flow.host_select.glbl_cfg',
         f'''
             [scheduler]
-                run hosts = {remote_platform}
-                ranking = """
-                    # if this test fails due to race conditions
-                    # then you are very lucky
-                    virtual_memory().available > 123456789123456789
-                    cpu_count() > 512
-                    disk_usage('/').free > 123456789123456789
-                """
+                [[run hosts]]
+                    available = {remote_platform}
+                    ranking = """
+                        # if this test fails due to race conditions
+                        # then you are very lucky
+                        virtual_memory().available > 123456789123456789
+                        cpu_count() > 512
+                        disk_usage('/').free > 123456789123456789
+                    """
         '''
     )
     with pytest.raises(HostSelectException) as excinfo:

From b4063e2ad0e61dabcc8a8256b09d9af14c79d898 Mon Sep 17 00:00:00 2001
From: Tim Pillinger <26465611+wxtim@users.noreply.github.com>
Date: Thu, 26 Nov 2020 10:44:02 +0000
Subject: [PATCH 4/7] moved suite host self-identification to schediler section

---
 cylc/flow/cfgspec/globalcfg.py                | 89 ++++++++++---------
 cylc/flow/hostuserutil.py                     |  6 +-
 tests/functional/lib/bash/test_header         |  2 +-
 .../suite-host-self-id/00-address.t           |  7 +-
 4 files changed, 54 insertions(+), 50 deletions(-)

diff --git a/cylc/flow/cfgspec/globalcfg.py b/cylc/flow/cfgspec/globalcfg.py
index c5bd54b36f1..1da5b4d3400 100644
--- a/cylc/flow/cfgspec/globalcfg.py
+++ b/cylc/flow/cfgspec/globalcfg.py
@@ -139,6 +139,52 @@
                 to filter by cpu_percent() < 70 then to rank by cpu_percent.
             ''')
 
+        with Conf('host self-identification', desc='''
+            The suite host's identity must be determined locally by cylc and
+            passed to running tasks (via ``$CYLC_SUITE_HOST``) so that task
+            messages can target the right suite on the right host.
+
+            .. todo
+            Is it conceivable that different remote task hosts at the same site
+            might see the suite host differently? If so we would need to be
+            able to override the target in suite configurations.
+        '''):
+            Conf('method', VDR.V_STRING, 'name', options=[
+                'name', 'address', 'hardwired'
+                ],
+                desc='''
+                This item determines how cylc finds the identity of the suite
+                host.For the default *name* method cylc asks the suite host
+                for its host name. This should resolve on remote task hosts to
+                the IP address of the suite host; if it doesn't, adjust
+                network settings or use one of the other methods. For the
+                *address* method, cylc attempts to use a special external
+                "target address" to determine the IP address of the suite
+                host as seen by remote task hosts.  And finally, as a
+                last resort, you can choose the *hardwired* method and manually
+                specify the host name or IP address of the suite host.
+
+                Options:
+
+                name
+                Self-identified host name.
+                address
+                Automatically determined IP address (requires *target*).
+                hardwired
+                Manually specified host name or IP address (requires *host*).
+            ''')
+            Conf('target', VDR.V_STRING, 'google.com', desc='''
+                This item is required for the *address* self-identification
+                method. If your suite host sees the internet, a common address
+                such as ``google.com`` will do; otherwise choose a host
+                visible on your intranet.
+            ''')
+            Conf('host', VDR.V_STRING, desc='''
+                Use this item to explicitly set the name or IP address of the
+                suite host if you have to use the *hardwired*
+                self-identification method.
+            ''')
+
         with Conf('events', desc='''
             You can define site defaults for each of the following options,
             details of which can be found under
@@ -573,49 +619,6 @@
         Conf('from', VDR.V_STRING)
         Conf('to', VDR.V_STRING)
 
-    # suite
-    with Conf('suite host self-identification', desc='''
-        The suite host's identity must be determined locally by cylc and passed
-        to running tasks (via ``$CYLC_SUITE_HOST``) so that task messages can
-        target the right suite on the right host.
-
-        .. todo
-           Is it conceivable that different remote task hosts at the same site
-           might see the suite host differently? If so we would need to be able
-           to override the target in suite configurations.
-    '''):
-        Conf('method', VDR.V_STRING, 'name',
-             options=['name', 'address', 'hardwired'], desc='''
-            This item determines how cylc finds the identity of the suite host.
-            For the default *name* method cylc asks the suite host for its host
-            name. This should resolve on remote task hosts to the IP address of
-            the suite host; if it doesn't, adjust network settings or use one
-            of the other methods. For the *address* method, cylc attempts to
-            use a special external "target address" to determine the IP address
-            of the suite host as seen by remote task hosts.  And finally, as a
-            last resort, you can choose the *hardwired* method and manually
-            specify the host name or IP address of the suite host.
-
-            Options:
-
-            name
-               Self-identified host name.
-            address
-               Automatically determined IP address (requires *target*).
-            hardwired
-               Manually specified host name or IP address (requires *host*).
-        ''')
-        Conf('target', VDR.V_STRING, 'google.com', desc='''
-            This item is required for the *address* self-identification method.
-            If your suite host sees the internet, a common address such as
-            ``google.com`` will do; otherwise choose a host visible on your
-            intranet.
-        ''')
-        Conf('host', VDR.V_STRING, desc='''
-            Use this item to explicitly set the name or IP address of the suite
-            host if you have to use the *hardwired* self-identification method.
-        ''')
-
 
 def upg(cfg, descr):
     """Upgrader."""
diff --git a/cylc/flow/hostuserutil.py b/cylc/flow/hostuserutil.py
index f1ff39dd55a..21e51735ed2 100644
--- a/cylc/flow/hostuserutil.py
+++ b/cylc/flow/hostuserutil.py
@@ -125,13 +125,13 @@ def _get_host_info(self, target=None):
     @staticmethod
     def _get_identification_cfg(key):
         """Return the [suite host self-identification]key global conf."""
-        return glbl_cfg().get(['suite host self-identification', key])
+        return glbl_cfg().get(['scheduler', 'host self-identification', key])
 
     def get_host(self):
         """Return the preferred identifier for the suite (or current) host.
 
-        As specified by the "suite host self-identification" settings in the
-        site/user global.cylc files. This is mainly used for suite host
+        As specified by the "[scheduler][host self-identification]" settings in
+        the site/user global.cylc files. This is mainly used for suite host
         identification by task jobs.
 
         """
diff --git a/tests/functional/lib/bash/test_header b/tests/functional/lib/bash/test_header
index c3ea0436772..eeab952df51 100644
--- a/tests/functional/lib/bash/test_header
+++ b/tests/functional/lib/bash/test_header
@@ -700,7 +700,7 @@ create_test_global_config() {
     # Tidy in case of previous use of this function.
     rm -fr 'etc'
     mkdir 'etc'
-    # Suite host self-identification method.
+    # Scheduler host self-identification method.
     echo "$PRE" >'etc/global.cylc'
     USER_TESTS_CONF_FILE="${HOME}/.cylc/flow/$(cylc version)/global-tests.cylc"
     if [[ -f "${USER_TESTS_CONF_FILE}" ]]; then
diff --git a/tests/functional/suite-host-self-id/00-address.t b/tests/functional/suite-host-self-id/00-address.t
index cb24916dbab..308bc310733 100644
--- a/tests/functional/suite-host-self-id/00-address.t
+++ b/tests/functional/suite-host-self-id/00-address.t
@@ -31,15 +31,16 @@ __PYTHON__
 
 #-------------------------------------------------------------------------------
 MY_INET_TARGET=$( \
-    cylc get-global-config '--item=[suite host self-identification]target')
+    cylc get-global-config '--item=[scheduler][host self-identification]target')
 MY_HOST_IP="$(get_local_ip_address "${MY_INET_TARGET}")"
 
 run_ok "${TEST_NAME_BASE}-validate" \
     cylc validate "${SUITE_NAME}" "--set=MY_HOST_IP=${MY_HOST_IP}"
 
 create_test_global_config '' '
-[suite host self-identification]
-    method = address'
+[scheduler]
+    [[host self-identification]]
+        method = address'
 suite_run_ok "${TEST_NAME_BASE}-run" \
     cylc run --reference-test --debug --no-detach "${SUITE_NAME}" \
     "--set=MY_HOST_IP=${MY_HOST_IP}"

From 24fd8406b5b2a731ab54d62c7f6fd94de4303ded Mon Sep 17 00:00:00 2001
From: Tim Pillinger <26465611+wxtim@users.noreply.github.com>
Date: Thu, 26 Nov 2020 11:53:04 +0000
Subject: [PATCH 5/7] Update cylc/flow/cfgspec/globalcfg.py

Co-authored-by: Ronnie Dutta <61982285+MetRonnie@users.noreply.github.com>
---
 cylc/flow/cfgspec/globalcfg.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/cylc/flow/cfgspec/globalcfg.py b/cylc/flow/cfgspec/globalcfg.py
index 1da5b4d3400..eb9874cba27 100644
--- a/cylc/flow/cfgspec/globalcfg.py
+++ b/cylc/flow/cfgspec/globalcfg.py
@@ -102,11 +102,11 @@
             The number of old run directory trees to retain at start-up.
         ''')
         with Conf('run hosts', desc='''
-        Configure allowed suite hosts and ports for starting up (running or
-        restarting) suites. Additionally configure host selection settings
-        specifying how to determine the most suitable run host at any given
-        time from those configured.
-    '''):
+            Configure allowed suite hosts and ports for starting up (running or
+            restarting) suites. Additionally configure host selection settings
+            specifying how to determine the most suitable run host at any given
+            time from those configured.
+        '''):
             Conf('available', VDR.V_SPACELESS_STRING_LIST, desc='''
                 A list of allowed suite run hosts. One of these hosts will be
                 appointed for a suite to start up on if an explicit host is not

From 1aa283c83cf02abe434ec49fb443d556a8defdeb Mon Sep 17 00:00:00 2001
From: Tim Pillinger <26465611+wxtim@users.noreply.github.com>
Date: Thu, 26 Nov 2020 11:53:35 +0000
Subject: [PATCH 6/7] Update cylc/flow/cfgspec/globalcfg.py

Co-authored-by: Ronnie Dutta <61982285+MetRonnie@users.noreply.github.com>
---
 cylc/flow/cfgspec/globalcfg.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/cylc/flow/cfgspec/globalcfg.py b/cylc/flow/cfgspec/globalcfg.py
index eb9874cba27..d395f9ed3cc 100644
--- a/cylc/flow/cfgspec/globalcfg.py
+++ b/cylc/flow/cfgspec/globalcfg.py
@@ -112,10 +112,9 @@
                 appointed for a suite to start up on if an explicit host is not
                 provided as an option to a ``run`` or ``restart`` command.
             ''')
-            Conf(
-                'ports', VDR.V_INTEGER_LIST, list(range(43001, 43101)),
-                desc='''
-                    A list of allowed ports for Cylc to use to run suites.
+            Conf('ports', VDR.V_INTEGER_LIST, list(range(43001, 43101)),
+                 desc='''
+                A list of allowed ports for Cylc to use to run suites.
             ''')
             Conf('condemned', VDR.V_ABSOLUTE_HOST_LIST, desc='''
                 Hosts specified in ``condemned hosts`` will not be considered

From bdeac72e1996469bf06d8558a22117b3eab590df Mon Sep 17 00:00:00 2001
From: Tim Pillinger <26465611+wxtim@users.noreply.github.com>
Date: Thu, 26 Nov 2020 12:02:25 +0000
Subject: [PATCH 7/7] moved auto restart delay

---
 cylc/flow/cfgspec/globalcfg.py                | 64 ++++++++++---------
 cylc/flow/main_loop/auto_restart.py           | 15 +++--
 .../restart/37-auto-restart-delay.t           |  4 +-
 .../43-auto-restart-force-override-normal.t   |  2 +-
 4 files changed, 46 insertions(+), 39 deletions(-)

diff --git a/cylc/flow/cfgspec/globalcfg.py b/cylc/flow/cfgspec/globalcfg.py
index d395f9ed3cc..20f396e6afd 100644
--- a/cylc/flow/cfgspec/globalcfg.py
+++ b/cylc/flow/cfgspec/globalcfg.py
@@ -101,6 +101,14 @@
              desc='''
             The number of old run directory trees to retain at start-up.
         ''')
+        Conf('auto restart delay', VDR.V_INTERVAL, desc='''
+            Relates to Cylc's auto stop-restart mechanism (see
+            :ref:`auto-stop-restart`).  When a host is set to automatically
+            shutdown/restart it will first wait a random period of time
+            between zero and ``auto restart delay`` seconds before
+            beginning the process. This is to prevent large numbers of
+            suites from restarting simultaneously.
+        ''')
         with Conf('run hosts', desc='''
             Configure allowed suite hosts and ports for starting up (running or
             restarting) suites. Additionally configure host selection settings
@@ -122,14 +130,6 @@
                 ``condemned hosts`` they will be automatically shutdown and
                 restarted (see:ref:`auto-stop-restart`).
             ''')
-            Conf('auto restart delay', VDR.V_INTERVAL, desc='''
-                Relates to Cylc's auto stop-restart mechanism (see
-                :ref:`auto-stop-restart`).  When a host is set to automatically
-                shutdown/restart it will first wait a random period of time
-                between zero and ``auto restart delay`` seconds before
-                beginning the process. This is to prevent large numbers of
-                suites from restarting simultaneously.
-            ''')
             Conf('ranking', VDR.V_STRING, desc='''
                 A multiline string containing Python expressions to filter
                 and/or rank hosts. For example:
@@ -148,29 +148,33 @@
             might see the suite host differently? If so we would need to be
             able to override the target in suite configurations.
         '''):
-            Conf('method', VDR.V_STRING, 'name', options=[
-                'name', 'address', 'hardwired'
-                ],
+            Conf(
+                'method', VDR.V_STRING, 'name',
+                options=['name', 'address', 'hardwired'],
                 desc='''
-                This item determines how cylc finds the identity of the suite
-                host.For the default *name* method cylc asks the suite host
-                for its host name. This should resolve on remote task hosts to
-                the IP address of the suite host; if it doesn't, adjust
-                network settings or use one of the other methods. For the
-                *address* method, cylc attempts to use a special external
-                "target address" to determine the IP address of the suite
-                host as seen by remote task hosts.  And finally, as a
-                last resort, you can choose the *hardwired* method and manually
-                specify the host name or IP address of the suite host.
-
-                Options:
-
-                name
-                Self-identified host name.
-                address
-                Automatically determined IP address (requires *target*).
-                hardwired
-                Manually specified host name or IP address (requires *host*).
+                    This item determines how cylc finds the identity of the
+                    suite host.For the default *name* method cylc asks the
+                    suite host
+                    for its host name. This should resolve on remote task
+                    hosts to
+                    the IP address of the suite host; if it doesn't, adjust
+                    network settings or use one of the other methods. For the
+                    *address* method, cylc attempts to use a special external
+                    "target address" to determine the IP address of the suite
+                    host as seen by remote task hosts.  And finally, as a
+                    last resort, you can choose the *hardwired* method and
+                    manually
+                    specify the host name or IP address of the suite host.
+
+                    Options:
+
+                    name
+                    Self-identified host name.
+                    address
+                    Automatically determined IP address (requires *target*).
+                    hardwired
+                    Manually specified host name or IP address (requires
+                    *host*).
             ''')
             Conf('target', VDR.V_STRING, 'google.com', desc='''
                 This item is required for the *address* self-identification
diff --git a/cylc/flow/main_loop/auto_restart.py b/cylc/flow/main_loop/auto_restart.py
index 811f5bab99e..141255f01b4 100644
--- a/cylc/flow/main_loop/auto_restart.py
+++ b/cylc/flow/main_loop/auto_restart.py
@@ -27,8 +27,8 @@
 .. cylc-scope:: global.cylc
 
 - :cylc:conf:`[scheduler]auto restart delay`
-- :cylc:conf:`[scheduler]condemned hosts`
-- :cylc:conf:`[scheduler]run hosts`
+- :cylc:conf:`[scheduler][run hosts]condemned`
+- :cylc:conf:`[scheduler][run hosts]available`
 
 .. cylc-scope:: global.cylc[scheduler]
 
@@ -57,8 +57,9 @@
 .. code-block:: cylc
 
    [scheduler]
-       run hosts = pub
-       condemned hosts = foo, bar!
+        [[run hosts]]
+       available = pub
+       condemned = foo, bar!
 
 .. warning::
 
@@ -67,9 +68,11 @@
    are evaluated on the suite host server.
 
 To prevent large numbers of suites attempting to restart simultaneously the
-:cylc:conf:`auto restart delay` setting defines a period of time in seconds.
+:cylc:conf:`[scheduler]auto restart delay` setting defines a period of time in
+seconds.
 Suites will wait for a random period of time between zero and
-:cylc:conf:`auto restart delay` seconds before attempting to stop and restart.
+:cylc:conf:`[scheduler]auto restart delay` seconds before attempting to stop
+and restart.
 
 Suites that are started up in no-detach mode cannot auto stop-restart on a
 different host - as it will still end up attached to the condemned host.
diff --git a/tests/functional/restart/37-auto-restart-delay.t b/tests/functional/restart/37-auto-restart-delay.t
index e3bd0b65571..c51bda701b1 100644
--- a/tests/functional/restart/37-auto-restart-delay.t
+++ b/tests/functional/restart/37-auto-restart-delay.t
@@ -54,9 +54,9 @@ MAX_RESTART_DELAY=30
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
 [scheduler]
+    auto restart delay = PT${MAX_RESTART_DELAY}S
     [[run hosts]]
         available = localhost
-        auto restart delay = PT${MAX_RESTART_DELAY}S
 "
 
 # Run suite.
@@ -67,10 +67,10 @@ poll_suite_running
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
 [scheduler]
+    auto restart delay = PT20S
     [[run hosts]]
         available = ${CYLC_TEST_HOST}
         condemned = $(hostname)
-        auto restart delay = PT20S
 "
 
 # Check stop-restart working.
diff --git a/tests/functional/restart/43-auto-restart-force-override-normal.t b/tests/functional/restart/43-auto-restart-force-override-normal.t
index 4299e245075..cfe1feab43f 100644
--- a/tests/functional/restart/43-auto-restart-force-override-normal.t
+++ b/tests/functional/restart/43-auto-restart-force-override-normal.t
@@ -63,10 +63,10 @@ FILE=$(cylc cat-log "${SUITE_NAME}" -m p |xargs readlink -f)
 create_test_global_config '' "
 ${BASE_GLOBAL_CONFIG}
 [scheduler]
+    auto restart delay = -PT60S  # results in +PT60S delay
     [[run hosts]]
         available = ${CYLC_TEST_HOST_1}, ${CYLC_TEST_HOST_2}
         condemned = ${CYLC_TEST_HOST_1}
-        auto restart delay = -PT60S  # results in +PT60S delay
 "
 log_scan "${TEST_NAME_BASE}-stop" "${FILE}" 40 1 \
     'The Cylc suite host will soon become un-available' \