Adding logging fields for collapsed forwarding metrics

doc/admin-guide/logging/formatting.en.rst

@@ -151,6 +151,9 @@ Cache Details
 .. _chm:
 .. _cwr:
 .. _cwtr:
+.. _crra:
+.. _cwra:
+.. _cccs:
 
 These log fields reveal details of the |TS| proxy interaction with its own
 cache while attempting to service incoming client requests.
@@ -173,6 +176,13 @@ cwr   Proxy Cache    Cache Write Result. Specifies the result of attempting to
                      (``WL_MISS``), write interrupted (``INTR``), error while
                      writing (``ERR``), or cache write successful (``FIN``).
 cwt   Proxy Cache    Cache Write Transform Result.
+crra  Proxy Cache    Cache read retry attempts to read the object from cache.
+cwra  Proxy Cache    Cache write retry attempts to write a fresh or updated
+                     object to cache.
+cccs  Proxy Cache    Cache collapsed connection success;
+                     -1: collapsing was attempted but failed, request went upstream
+                     0: collapsing was unnecessary
+                     1: attempted to collapse and got a cache hit on subsequent read attempts
 ===== ============== ==========================================================
 
 .. _admin-logging-fields-txn:

proxy/logging/Log.cc

@@ -892,6 +892,21 @@ Log::init_fields()
   global_field_list.add(field, false);
   field_symbol_hash.emplace("ctid", field);
 
+  field = new LogField("cache_read_retry_attempts", "crra", LogField::dINT, &LogAccess::marshal_cache_read_retries,
+                       &LogAccess::unmarshal_int_to_str);
+  global_field_list.add(field, false);
+  field_symbol_hash.emplace("crra", field);
+
+  field = new LogField("cache_write_retry_attempts", "cwra", LogField::dINT, &LogAccess::marshal_cache_write_retries,
+                       &LogAccess::unmarshal_int_to_str);
+  global_field_list.add(field, false);
+  field_symbol_hash.emplace("cwra", field);
+
+  field = new LogField("cache_collapsed_connection_success", "cccs", LogField::dINT,
+                       &LogAccess::marshal_cache_collapsed_connection_success, &LogAccess::unmarshal_int_to_str);
+  global_field_list.add(field, false);
+  field_symbol_hash.emplace("cccs", field);
+
   field = new LogField("client_transaction_priority_weight", "ctpw", LogField::sINT,
                        &LogAccess::marshal_client_http_transaction_priority_weight, &LogAccess::unmarshal_int_to_str);
   global_field_list.add(field, false);

proxy/logging/LogAccess.cc

@@ -2631,6 +2631,61 @@ LogAccess::marshal_client_http_transaction_priority_dependence(char *buf)
   return INK_MIN_ALIGN;
 }
 
+/*-------------------------------------------------------------------------
+  -------------------------------------------------------------------------*/
+
+int
+LogAccess::marshal_cache_read_retries(char *buf)
+{
+  if (buf) {
+    int64_t id = 0;
+    if (m_http_sm) {
+      id = m_http_sm->get_cache_sm().get_open_read_tries();
+    }
+    marshal_int(buf, id);
+  }
+  return INK_MIN_ALIGN;
+}
+
+/*-------------------------------------------------------------------------
+  -------------------------------------------------------------------------*/
+
+int
+LogAccess::marshal_cache_write_retries(char *buf)
+{
+  if (buf) {
+    int64_t id = 0;
+    if (m_http_sm) {
+      id = m_http_sm->get_cache_sm().get_open_write_tries();
+    }
+    marshal_int(buf, id);
+  }
+  return INK_MIN_ALIGN;
+}
+
+int
+LogAccess::marshal_cache_collapsed_connection_success(char *buf)
+{
+  if (buf) {
+    int64_t id = 0; // default - no collapse attempt
+    if (m_http_sm) {
+      SquidLogCode code = m_http_sm->t_state.squid_codes.log_code;
+
+      // We increment open_write_tries beyond the max when we want to jump back to the read state for collapsing
+      if ((m_http_sm->get_cache_sm().get_open_write_tries() > (m_http_sm->t_state.txn_conf->max_cache_open_write_retries)) &&
+          ((code == SQUID_LOG_TCP_HIT) || (code == SQUID_LOG_TCP_MEM_HIT) || (code == SQUID_LOG_TCP_DISK_HIT))) {
+        // Attempted collapsed connection and got a hit, success
+        id = 1;
+      } else if (m_http_sm->get_cache_sm().get_open_write_tries() > (m_http_sm->t_state.txn_conf->max_cache_open_write_retries)) {
+        // Attempted collapsed connection with no hit, failure, we can also get +2 retries in a failure state
+        id = -1;
+      }
+    }
+
+    marshal_int(buf, id);
+  }
+  return INK_MIN_ALIGN;
+}
 /*-------------------------------------------------------------------------
   -------------------------------------------------------------------------*/
 

proxy/logging/LogAccess.h

@@ -252,6 +252,9 @@ class LogAccess
   inkcoreapi int marshal_cache_lookup_url_canon(char *);                      // STR
   inkcoreapi int marshal_client_sni_server_name(char *);                      // STR
   inkcoreapi int marshal_version_build_number(char *);                        // STR
+  inkcoreapi int marshal_cache_read_retries(char *);                          // INT
+  inkcoreapi int marshal_cache_write_retries(char *);                         // INT
+  inkcoreapi int marshal_cache_collapsed_connection_success(char *);          // INT
 
   // named fields from within a http header
   //