Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Use manifest to persist pre-allocated seqnos #11995

Closed
wants to merge 1 commit into from

Conversation

pdillinger
Copy link
Contributor

@pdillinger pdillinger commented Oct 21, 2023

Summary: ... and other fixes for crash test after #11922.

  • When pre-allocating sequence numbers for establishing a time history, record that last sequence number in the manifest so that it is (most likely) restored on recovery even if no user writes were made or were recovered (e.g. no WAL).
  • When pre-allocating sequence numbers for establishing a time history, only do this for actually new DBs.
  • Remove the feature that ensures non-zero sequence number on creating the first column family with preserve/preclude option after initial DB::Open. Until fixed in a way compatible with the crash test, this creates a gap where some data written with active preserve/preclude option won't have a known associated time.

Together, these ensure we don't upset the crash test by manipulating sequence numbers after initial DB creation (esp when re-opening with different options). (The crash test expects that the seqno after re-open corresponds to a known point in time from previous crash test operation, matching an expected DB state.)

Follow-up work:

  • Re-fill the gap to ensure all data written under preserve/preclude settings have a known time estimate.

Test Plan: Added to unit test SeqnoTimeTablePropTest.PrePopulateInDB

Verified fixes two crash test scenarios:

1st reproducer

First apply

diff --git a/db_stress_tool/expected_state.cc b/db_stress_tool/expected_state.cc
index b483e154c..ef63b8d6c 100644
--- a/db_stress_tool/expected_state.cc
+++ b/db_stress_tool/expected_state.cc
@@ -333,6 +333,7 @@ Status FileExpectedStateManager::SaveAtAndAfter(DB* db) {
     s = NewFileTraceWriter(Env::Default(), soptions, trace_file_path,
                            &trace_writer);
   }
+  if (getenv("CRASH")) assert(false);
   if (s.ok()) {
     TraceOptions trace_opts;
     trace_opts.filter |= kTraceFilterGet;

Then

mkdir -p /dev/shm/rocksdb_test/rocksdb_crashtest_expected
mkdir -p /dev/shm/rocksdb_test/rocksdb_crashtest_whitebox
rm -rf /dev/shm/rocksdb_test/rocksdb_crashtest_*/*
CRASH=1 ./db_stress --db=/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox --expected_values_dir=/dev/shm/rocksdb_test/rocksdb_crashtest_expected --destroy_db_initially=1 --manual_wal_flush_one_in=1000000 --clear_column_family_one_in=0 --preserve_internal_time_seconds=36000
./db_stress --db=/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox --expected_values_dir=/dev/shm/rocksdb_test/rocksdb_crashtest_expected --destroy_db_initially=0 --manual_wal_flush_one_in=1000000 --clear_column_family_one_in=0 --preserve_internal_time_seconds=0

Without the fix you get

...
DB path: [/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox]
(Re-)verified 34 unique IDs
Error restoring historical expected values: Corruption: DB is older than any restorable expected state

2nd reproducer

First apply

diff --git a/db_stress_tool/db_stress_test_base.cc b/db_stress_tool/db_stress_test_base.cc
index 62ddead7b..f2654980f 100644
--- a/db_stress_tool/db_stress_test_base.cc
+++ b/db_stress_tool/db_stress_test_base.cc
@@ -1126,6 +1126,7 @@ void StressTest::OperateDb(ThreadState* thread) {
         // OPERATION write
         TestPut(thread, write_opts, read_opts, rand_column_families, rand_keys,
                 value);
+        if (getenv("CRASH")) assert(false);
       } else if (prob_op < del_bound) {
         assert(write_bound <= prob_op);
         // OPERATION delete

Then

rm -rf /dev/shm/rocksdb_test/rocksdb_crashtest_*/*
CRASH=1 ./db_stress --db=/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox --expected_values_dir=/dev/shm/rocksdb_test/rocksdb_crashtest_expected --destroy_db_initially=1 --manual_wal_flush_one_in=1000000 --clear_column_family_one_in=0 --disable_wal=1 --reopen=0 --preserve_internal_time_seconds=0
./db_stress --db=/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox --expected_values_dir=/dev/shm/rocksdb_test/rocksdb_crashtest_expected --destroy_db_initially=0 --manual_wal_flush_one_in=1000000 --clear_column_family_one_in=0 --disable_wal=1 --reopen=0 --preserve_internal_time_seconds=3600

Without the fix you get

DB path: [/dev/shm/rocksdb_test/rocksdb_crashtest_whitebox]
(Re-)verified 34 unique IDs
db_stress: db_stress_tool/expected_state.cc:380: virtual rocksdb::{anonymous}::ExpectedStateTraceRecordHandler::~
ExpectedStateTraceRecordHandler(): Assertion `IsDone()' failed. 

Summary: ... and other fixes for crash test after facebook#11922.
* When pre-allocating sequence numbers for establishing a time history,
record that last sequence number in the manifest so that it is (most
likely) restored on recovery even if no user writes were made or were
recovered (e.g. no WAL).
* When pre-allocating sequence numbers for establishing a time history,
only do this for actually new DBs.
* Remove the feature that ensures non-zero sequence number on creating
the first column family with preserve/preclude option after initial
DB::Open. Until fixed in a way compatible with the crash test, this
creates a gap where some data written with active preserve/preclude
option won't have a known associated time.

Together, these ensure we don't upset the crash test by manipulating
sequence numbers after initial DB creation (esp when re-opening with
different options). (The crash test expects that the seqno after re-open
corresponds to a known point in time from previous crash test
operation, matching an expected DB state.)

Test Plan: Added to unit test SeqnoTimeTablePropTest.PrePopulateInDB

TODO check crash test
@facebook-github-bot
Copy link
Contributor

@pdillinger has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

Copy link
Contributor

@jowlyzhang jowlyzhang left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM, thanks @pdillinger for the quick fix!

@facebook-github-bot
Copy link
Contributor

@pdillinger merged this pull request in 4155087.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Projects
None yet
Development

Successfully merging this pull request may close these issues.

3 participants