… down for a system reboot. The pmp-check-mysql-pidfile plugin verifies that MySQL‘s PID file exists. Evidence of contention in… is allocating too much memory. A runaway server process, or poorly optimized queries, can consume too much memory and cause the server… pmp-check-unix-memory plugin checks for a single process consuming too much memory and/or for too little free memory in general. This…
Post: InnoDB memory allocation, ulimit, and OpenSUSE
August 23, 2010 By 7 Comments
… the extra 3.37 GB allocation, there was still some free memory. Or was there? Maybe some hidden monster was eating it…. Apparenly OpenSUSE defaults are set in proportion to physical memory to keep the memory-hungry applications from taking the system down. On… physical memory, 2 GB swap it decided to set the virtual memory ulimit (-v) to 77.27 GB, and the physical memory (-m…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
… great feature called “Query Cache” which is quite helpful for MySQL Performance optimization tasks but there are number of things you… can be seen as large value of Qcache_free_blocks relatively to Qcache_free_memory. FLUSH QUERY CACHE command can be used for… and watch Qcache_free_memory and Qcache_lowmem_prunes – If you’re not getting much of lowmem_prunes and free_memory stays high you…
Post: Memory allocation in Stored Function
August 26, 2007 By 8 Comments
… with no free memory and giant swap. The case was worth to look deeply – let’s try simple table (experiments with MySQL 5… check only select: mysql> select avg(length(hello(name))) from testf; and here is vmstat 5 output: procs ———–memory———- —swap– —–io—- –system… As you see MySQL ate 5GB of memory in 85 sec. That makes things clearer. As I understand MySQL allocates memory in each call…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 5 Comments
…memory is being used by current MEMORY tables: mysql> select sum(data_length+index_length) from information_schema.tables where engine=’memory‘; …406936 + 18144) Dictionary memory allocated 2623331 Buffer pool size 7864319 Buffer pool size, bytes 128849002496 Free buffers 1 Database…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
…: mtr_commit (sync0sync.ic:221) ==9090== by 0x6B39223: fsp_fill_free_list (fsp0fsp.c:1455) ==9090== by 0x6B3DED8: fsp_header_init… the waiters field next, the read must be serialized in memory after the reset. A speculative processor might perform the read…, I’d consider backporting and using MySQL 5.5 atomic operation primitives with proper memory barriers, so that there is no need…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… ? You can take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql# cat /proc/19018/stat 19018 (mysqld) S… how “wait free your system is”. If it system is already have low wait ratio increasing amount of memory for example is… to use this information is to compare systems with different memory amount having same workload. You will often see increasing amount…
Post: How Much memory do you use to run MySQL
November 2, 2012 By 8 Comments
We have seen number of issues with MySQL Server related to amount of memory you have in the system – these range from… I wonder how much memory do we really use to run MySQL Server these days ? [poll id="2"] Feel free to select multiple…
Post: Flexviews is a working scalable database transactional memory example
May 19, 2011 By 3 Comments
… tool is for MySQL, but the methods are database agnostic. A materialized view is an analogue of software transactional memory. You can think of this as database transactional memory, or as database state distributed over…, particularly if there are thorough database checks. Flexviews is: lock free for read fully log based supports all DML supports all…
Post: Is MySQL 5.6 slower than MySQL 5.5?
February 18, 2013 By 23 Comments
… though Performance Schema overhead was reduced in MySQL 5.6 it is still not free and it will cause an overhead, yet… small (1M rows) benchmark so data was well fitting in memory and Read Only one to simplify things and get more…_5_6_10# sysbench –test=oltp –mysql-socket=/tmp/mysql_sandbox5610.sock –mysql-user=msandbox_rw –mysql-password=msandbox –oltp-table-size=1000000 –num…
