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WITH LARGE BUFFER POOL (Note: this a backport of revno:3472 from mysql-trunk) rb://845 approved by: Marko When dropping a table (with an .ibd file i.e.: with innodb_file_per_table set) we scan entire LRU to invalidate pages from that table. This can be painful in case of large buffer pools as we hold the buf_pool->mutex for the scan. Note that gravity of the problem does not depend on the size of the table. Even with an empty table but a large and filled up buffer pool we'll end up scanning a very long LRU list. The fix is to scan flush_list and just remove the blocks belonging to the table from the flush_list, marking them as non-dirty. The blocks are left in the LRU list for eventual eviction due to aging. The flush_list is typically much smaller than the LRU list but for cases where it is very long we have the solution of releasing the buf_pool->mutex after scanning 1K pages. buf_page_[set|unset]_sticky(): Use new IO-state BUF_IO_PIN to ensure that a block stays in the flush_list and LRU list when we release buf_pool->mutex. Previously we have been abusing BUF_IO_READ to achieve this.
60 lines
1.3 KiB
Plaintext
60 lines
1.3 KiB
Plaintext
-- source include/have_innodb.inc
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let $per_table=`select @@innodb_file_per_table`;
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let $format=`select @@innodb_file_format`;
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-- let $query_i_s = SELECT page_size FROM information_schema.innodb_cmpmem WHERE pages_used > 0
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set global innodb_file_per_table=on;
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set global innodb_file_format=`1`;
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create table t1(a text) engine=innodb key_block_size=8;
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-- disable_query_log
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# insert some rows so we are using compressed pages
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-- let $i = 10
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while ($i)
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{
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insert into t1 values(repeat('abcdefghijklmnopqrstuvwxyz',100));
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dec $i;
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}
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-- enable_query_log
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# we should be using some 8K pages
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-- eval $query_i_s
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drop table t1;
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# because of lazy eviction at drop table in 5.5 there should be some
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# used 8K pages
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-- eval $query_i_s
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# create a non-compressed table and insert enough into it to evict
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# compressed pages
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create table t2(a text) engine=innodb;
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-- disable_query_log
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-- let $i = 400
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while ($i)
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{
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insert into t2 values(repeat('abcdefghijklmnopqrstuvwxyz',1000));
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dec $i;
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}
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-- enable_query_log
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# now there should be no 8K pages in the buffer pool
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-- eval $query_i_s
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drop table t2;
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#
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# restore environment to the state it was before this test execution
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#
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-- disable_query_log
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eval set global innodb_file_format=$format;
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eval set global innodb_file_per_table=$per_table;
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