Make Rdb_transaction_impl::get_trx safe to call from other threads #1512
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@luqun has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
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could you add a MTR for this if possible? |
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Patch: diff --git a/storage/rocksdb/ha_rocksdb.cc b/storage/rocksdb/ha_rocksdb.cc
index 0727fc66a87..b091e141292 100644
--- a/storage/rocksdb/ha_rocksdb.cc
+++ b/storage/rocksdb/ha_rocksdb.cc
@@ -5407,6 +5407,9 @@ class Rdb_transaction_impl : public Rdb_transaction {
assert(get_statement_snapshot_type() == snapshot_type::NONE);
assert_snapshot_invariants();
assert(m_rocksdb_reuse_tx[TABLE_TYPE::USER_TABLE] == nullptr);
+
+ DEBUG_SYNC(m_thd, "myrocks_release_tx");
+
auto tx = std::move(m_rocksdb_tx[TABLE_TYPE::USER_TABLE]);
if (rocksdb_write_batch_mem_free_threshold > 0 &&
wb_size > rocksdb_write_batch_mem_free_threshold) {
@@ -7740,6 +7743,9 @@ class Rdb_trx_info_aggregator : public Rdb_tx_list_walker {
const int is_replication = (thd->rli_slave != nullptr);
uint32_t waiting_cf_id;
std::string waiting_key;
+
+ DEBUG_SYNC(current_thd, "myrocks_in_rocksdb_trx_with_trx");
+
rdb_trx->GetWaitingTxns(&waiting_cf_id, &waiting_key),
m_trx_info->push_back(
Test: Output: |
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The testcase does not port directly to the fix branch because one of the debug sync points ends up in the fixing mutex critical section |
- Introduce Rdb_transaction_impl::m_rdb_tx_mutex to protect writes to m_rocksdb_tx[USER_TABLE] from the query thread and reads from other threads. - To protect query thread writes, add critical sections to begin_rdb_tx and release_tx methods. - Make get_rdb_trx lock this mutex before returning the RocksDB transaction pointer and introduce unlock_rdb_trx method to unlock this mutex. - Call the above methods in Rdb_trx_info_aggregator::process_tran. Move unrelated code out of this critical section.
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@laurynas-biveinis has updated the pull request. You must reimport the pull request before landing. |
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@luqun, ready for review again |
luqun
reviewed
Jan 27, 2025
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@luqun has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator. |
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This pull request has been merged in c6e4b9f. |
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m_rocksdb_tx[USER_TABLE] from the query thread and reads from other threads.
release_tx methods.
pointer and introduce unlock_rdb_trx method to unlock this mutex.
unrelated code out of this critical section.