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scylladb/test/cluster/test_compaction_backpressure.py
Avi Kivity 0ae22a09d4 LICENSE: Update to version 1.1
Updated terms of non-commercial use (must be a never-customer).
2026-04-12 19:46:33 +03:00

77 lines
3.7 KiB
Python

#
# Copyright (C) 2025-present ScyllaDB
#
# SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.1
#
from test.pylib.manager_client import ManagerClient
from test.pylib.tablets import get_tablet_replica
from test.pylib.rest_client import inject_error_one_shot, inject_error
from test.cluster.util import new_test_keyspace, new_test_table
from test.cqlpy import nodetool
import pytest
import asyncio
import logging
logger = logging.getLogger(__name__)
@pytest.mark.asyncio
@pytest.mark.skip_mode(mode='release', reason='error injections are not supported in release mode')
async def test_intranode_migration_not_blocked_by_backpressure(manager: ManagerClient):
"""
Reproducer for a bug where intra-node tablet migration gets stuck
in maybe_wait_for_sstable_count_reduction() because the compaction
manager's regular_compaction_task_executor::do_run() returns early
(descriptor.sstables is empty) without signaling compaction_done.
The flush triggered by clone_locally_tablet_storage() calls
maybe_wait_for_sstable_count_reduction() which waits on
compaction_done. If compaction returns early without signaling,
the wait hangs forever.
The test uses two error injections:
1. maybe_wait_for_sstable_count_reduction_wait_on_compaction_done
(one-shot): Forces the flush path to wait on compaction_done,
simulating the backpressure condition.
2. compaction_regular_compaction_task_executor_do_run_empty_sstables
(non-one-shot): Forces do_run() to always return early with
empty sstables, simulating the case where the compaction
strategy finds nothing to compact.
Without the fix: do_run() returns early without signaling
compaction_done, the wait hangs forever, blocking the migration.
With the fix: do_run() signals compaction_done on early return,
waking up the waiter and allowing the migration to proceed.
"""
cmdline = ['--smp', '1']
servers = [await manager.server_add(cmdline=cmdline)]
cql = manager.get_cql()
extra_ks_param = "WITH replication = {'class': 'NetworkTopologyStrategy', 'replication_factor': 1} AND tablets = {'initial': 1}"
async with new_test_keyspace(manager, extra_ks_param) as ks:
extra_table_param = "WITH compaction = {'class' : 'IncrementalCompactionStrategy', 'max_threshold': 64} and compression = {}"
async with new_test_table(manager, ks, "pk int PRIMARY KEY, t text", extra_table_param) as cf:
table = cf.split('.')[-1]
await manager.api.disable_autocompaction(servers[0].ip_addr, ks)
# Write data and flush to create an sstable.
logger.info("Writing initial data and flushing")
for i in range(100):
await asyncio.gather(*[cql.run_async(f"INSERT INTO {cf} (pk, t) VALUES ({i}, '{'x' * 1020}')") for i in range(10*i, 10*(i+1))])
await manager.api.keyspace_flush(servers[0].ip_addr, ks, table)
# Write more data WITHOUT flushing
logger.info("Writing dirty data to memtable (no flush)")
await asyncio.gather(*[cql.run_async(f"INSERT INTO {cf} (pk, t) VALUES ({i}, '{'x' * 1020}')") for i in range(400, 410)])
logger.info("Enable autocompaction and trigger flush to simulate backpressure")
await manager.api.enable_injection(servers[0].ip_addr, "set_sstable_count_reduction_threshold", one_shot=False, parameters={'value': 32})
await manager.api.enable_autocompaction(servers[0].ip_addr, ks)
# With the bug, the flush hangs forever in maybe_wait_for_sstable_count_reduction().
# With the fix, it completes promptly.
await manager.api.keyspace_flush(servers[0].ip_addr, ks, table)