June 19, 2013

Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency

… labeled each query as Q{FLIGHT_NUMBER}.{QUERY_NUMBER}. …, but there are limitations which MyISAM imposes that…=/usr/local/mysql socket=/var/lib/mysql/mysql.sock user…cache=2048 table_definition_cache=16384 innodb_flush_method=O_DIRECT key_buffer_size=10G # Disabling symbolic-links is recommended

Post: Review of MySQL 5.6 Defaults Changes

…great summary of defaults changes in MySQL 5.6 compared to MySQL 5.5 In general there …give problems. I would recommend adding support for value 0 which would mean limit disabled. Very few …64K or even more would be good default. query_cache_size = 1M Query cache remains off by default but default …

Post: How Percona does a MySQL Performance Audit

… to analyze and present recommendations for your consideration, …clients | 205174 | | Aborted_connects | 29 | | Binlog_cache_disk_use | 0 | | Binlog_cache_use | 9630066 | | Bytes_received | …query log output. The stock MySQL server’s limitation of one-second granularity makes it hide problem queries

Comment: MySQL Server Memory Usage

…8M bulk_insert_buffer_size = 8M query_cache_limit = 254M query_cache_size = 254M query_cache_type = 1 query_prealloc_size = 65536 query_alloc_block_size = 131072 … mysql 3.x # clients (those using the mysqlclient10 compatibility package). #old_passwords=1 # Disabling symbolic-links is recommended

Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5

…of MySQL 5.5 and ~5 hours in case of MySQL 5.6 and MariaDB 5.5. Note that query cache is…choosing the query execution plan, is not sufficiently tuned and it is recommended to turn this off. The query used is:…_name, c_address, c_comment order by revenue desc LIMIT 20; In-memory workload Now let’s see …

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

…—-. 1 mysql mysql 98304 Feb 20 16:09 FTS_00000000000000ad_DELETED_CACHE.ibd -rw-rw—-. 1 mysql mysql …) mysql> delete from dir_test_innodb LIMIT 200000; Query OK, 200000 rows affected (8.65 sec) mysql> optimize… consultant, I might have a hard time recommending this feature to my customers, and as…

Comment: Database problems in MySQL/PHP Applications

query-time=5 log-slow-queries=/apps/log/slow-query interactive_timeout=300 wait_timeout=300 thread_cache = 40 max_connections=500 query_cache

Post: MySQL: Data Storage or Data Processing

…at recommendation task as well as a lot of other personalized services they may not use MySQL (and…have to do careful indexing build summary/cache tables hunt queries which traverse a lot of data and…data for you in parallel. You may argue limited number of applications needs so serious data crunches …

Post: More on dangers of the caches

… this case… MySQL was getting overloaded with thousands of same queries… which corresponded to cache miss storm…limit number of connections to MySQL and so let application to err when it tries to put too much load on MySQL as MySQL…some means to do that. I’d recommend doing it on user session so …

Post: MySQL Replication vs DRBD Battles

…memory and CPU cycles on double caching. Even in this case DRBD …the same time as running reporting queries on last month. All last … recommend to use DRBD with MySQL ? There some good reasons to use DRBD with MySQL…and hardware bugs rather than known limitations. You could argue depending on cases…