mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-13 18:02:24 +00:00
fb1a684d98
* Fix race in PageCache * Transportation security administration * Fix test flakiness, remove accidentally left over debug logging
107 lines
4.5 KiB
SQL
107 lines
4.5 KiB
SQL
-- Tags: no-fasttest, no-parallel
|
|
-- no-fasttest because we need an S3 storage policy
|
|
-- no-parallel because we look at server-wide counters about page cache usage
|
|
|
|
set use_page_cache_for_disks_without_file_cache = 1;
|
|
set page_cache_inject_eviction = 0;
|
|
set enable_filesystem_cache = 0;
|
|
set use_uncompressed_cache = 0;
|
|
|
|
create table events_snapshot engine Memory as select * from system.events;
|
|
create view events_diff as
|
|
-- round all stats to 70 MiB to leave a lot of leeway for overhead
|
|
with if(event like '%Bytes%', 70*1024*1024, 35) as granularity,
|
|
-- cache hits counter can vary a lot depending on other settings:
|
|
-- e.g. if merge_tree_min_bytes_for_concurrent_read is small, multiple threads will read each chunk
|
|
-- so we just check that the value is not too low
|
|
if(event in (
|
|
'PageCacheBytesUnpinnedRoundedToPages', 'PageCacheBytesUnpinnedRoundedToHugePages',
|
|
'PageCacheChunkDataHits'), 1, 1000) as clamp
|
|
select event, min2(intDiv(new.value - old.value, granularity), clamp) as diff
|
|
from system.events new
|
|
left outer join events_snapshot old
|
|
on old.event = new.event
|
|
where diff != 0 and
|
|
event in (
|
|
'ReadBufferFromS3Bytes', 'PageCacheChunkMisses', 'PageCacheChunkDataMisses',
|
|
'PageCacheChunkDataHits', 'PageCacheChunkDataPartialHits',
|
|
'PageCacheBytesUnpinnedRoundedToPages', 'PageCacheBytesUnpinnedRoundedToHugePages')
|
|
order by event;
|
|
|
|
drop table if exists page_cache_03055;
|
|
create table page_cache_03055 (k Int64 CODEC(NONE)) engine MergeTree order by k settings storage_policy = 's3_cache';
|
|
|
|
-- Write an 80 MiB file (40 x 2 MiB chunks), and a few small files.
|
|
system stop merges page_cache_03055;
|
|
insert into page_cache_03055 select * from numbers(10485760) settings max_block_size=100000000, preferred_block_size_bytes=1000000000;
|
|
|
|
select * from events_diff;
|
|
truncate table events_snapshot;
|
|
insert into events_snapshot select * from system.events;
|
|
|
|
system start merges page_cache_03055;
|
|
optimize table page_cache_03055 final;
|
|
truncate table events_snapshot;
|
|
insert into events_snapshot select * from system.events;
|
|
|
|
-- Cold read, should miss cache. (Populating cache on write is not implemented yet.)
|
|
|
|
select 'cold read', sum(k) from page_cache_03055;
|
|
|
|
select * from events_diff where event not in ('PageCacheChunkDataHits');
|
|
truncate table events_snapshot;
|
|
insert into events_snapshot select * from system.events;
|
|
|
|
-- Repeat read, should hit cache.
|
|
|
|
select 'repeat read 1', sum(k) from page_cache_03055;
|
|
|
|
select * from events_diff;
|
|
truncate table events_snapshot;
|
|
insert into events_snapshot select * from system.events;
|
|
|
|
-- Drop cache and read again, should miss. Also don't write to cache.
|
|
|
|
system drop page cache;
|
|
|
|
select 'dropped and bypassed cache', sum(k) from page_cache_03055 settings read_from_page_cache_if_exists_otherwise_bypass_cache = 1;
|
|
|
|
-- Data could be read multiple times because we're not writing to cache.
|
|
-- (Not checking PageCacheBytesUnpinned* because it's unreliable in this case because of an intentional race condition, see PageCache::evictChunk.)
|
|
select event, if(event in ('PageCacheChunkMisses', 'ReadBufferFromS3Bytes'), diff >= 1, diff) from events_diff where event not in ('PageCacheChunkDataHits', 'PageCacheBytesUnpinnedRoundedToPages', 'PageCacheBytesUnpinnedRoundedToHugePages');
|
|
truncate table events_snapshot;
|
|
insert into events_snapshot select * from system.events;
|
|
|
|
-- Repeat read, should still miss, but populate cache.
|
|
|
|
select 'repeat read 2', sum(k) from page_cache_03055;
|
|
|
|
select * from events_diff where event not in ('PageCacheChunkDataHits');
|
|
truncate table events_snapshot;
|
|
insert into events_snapshot select * from system.events;
|
|
|
|
-- Read again, hit the cache.
|
|
|
|
select 'repeat read 3', sum(k) from page_cache_03055 settings read_from_page_cache_if_exists_otherwise_bypass_cache = 1;
|
|
|
|
select * from events_diff;
|
|
truncate table events_snapshot;
|
|
insert into events_snapshot select * from system.events;
|
|
|
|
|
|
-- Known limitation: cache is not invalidated if a table is dropped and created again at the same path.
|
|
-- set allow_deprecated_database_ordinary=1;
|
|
-- create database test_03055 engine = Ordinary;
|
|
-- create table test_03055.t (k Int64) engine MergeTree order by k settings storage_policy = 's3_cache';
|
|
-- insert into test_03055.t values (1);
|
|
-- select * from test_03055.t;
|
|
-- drop table test_03055.t;
|
|
-- create table test_03055.t (k Int64) engine MergeTree order by k settings storage_policy = 's3_cache';
|
|
-- insert into test_03055.t values (2);
|
|
-- select * from test_03055.t;
|
|
|
|
|
|
drop table events_snapshot;
|
|
drop table page_cache_03055;
|
|
drop view events_diff;
|