… question arises how much logging impacts on performance. When we do performance audit often we log every query to find not only slow queries. A query… to log slow queries with execution time bigger than a second without worry about performance impact in case of CPU-bound workload. The performance impact is…
Post: Slow Query Log analyzes tools
September 6, 2006 By 83 Comments
…log all queries slow query log may be growing too rapidly to follow, so we implemented slow query log filter (based on parse_mysql_slow_log… reduce your performance a …logging only very slow queries. Once you have created full log – parse it and check queries using EXPLAIN starting from most impacted…
Post: Goal driven performance optimization
December 22, 2008 By Leave a Comment
…performance optimization tasks not only because of labor associated expenses but also because of the suffering – slow…-utime)/wtime) lost_ratio from performance_log_081221 where page_type=’search’ and wtime>1; … ones which cause the most impact and focus on optimizing them. …
Post: Impact of the number of idle connections in MySQL
December 17, 2010 By 20 Comments
… I found is not a small impact at all. For my daily work,…_pool_size=1G innodb_log_file_size=64M innodb_log_buffer_size=8M innodb…can see, the performance drop is shocking. At 1500 idle connections, the performance is 1…. the laptop (running dbt2) was not slowed down by handling all those connections….
Post: Testing the Group Commit Fix
July 13, 2011 By 13 Comments
… the results when we have a slow fsync (write-back cache is disabled), innodb_flush_log_at_trx_commit=1 and sync…. In order to summarize: the fix improves performance substantially when both innodb_flush_log_at_trx_commit=1 and sync_binlog=1… 1669.11 As you can see, enabling binary logs with system without writeback cache impacts performance significantly. And the similar with writeback cache…
Post: Four ways to optimize paginated displays
September 24, 2008 By 26 Comments
…at slow log analysis results (with our microslow patches, set to log all queries) for one client; the slow log …optimizing paginated displays that can give significantly better performance. On the first query, fetch and cache … of work off the database server without impacting the user’s experience …
Comment: Getting real life query speeds with MySQL
April 11, 2009 By 10 Comments
… “as is”, “load parallelization”, “think time reduction”, etc and generate performance issues root cause analysis on a spot. I used it… do load testing and get analytics RCA back (like slow-log data without any impact on a system and more), compare runs, etc…
Post: Effect of adaptive_flushing
December 4, 2009 By 5 Comments
…db pages 457902 Log flushed up to …performance because during those short periods of very high page write activity, the system and/or innodb can become very slow…performance impact… More aggressive flushing means more disk IO and possibly other impact on the system, which could impact…
Post: On Good Instrumentation
May 31, 2010 By 1 Comment
… Sometimes you may find the response time is impacted by queries from certain user, in others …queries or their performance. If I see 2 queries taking 30 seconds it is clearly slow queries. If…execute. Optional Tracing The information in lower layers logs is very helpful however it typically have two…
Post: Scaling: Consider both Size and Load
July 13, 2010 By 5 Comments
… data is very serious implication for system performance. Some queries have relatively small impact (having LOG(N) scalability), others may have linear or… in memory, now it is only 10%. The impact of cache on performance is very application dependent as well and may vary… seen things slowing down about 10x from less than 50% increase in the data size. I see the data size impact often…
