MySQL 5.5 and Percona Server 5.5 do not solve all scalability problems even for … than 8 cores effectively (which would correspond to single CPU socket these days) Here are some more details. oprofile:… pthread_cond_wait,os_cond_wait,os_event_wait_low,sync_array_wait_event,mutex_spin_wait,mutex_enter…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
… state, it is likely that if other CPU cores will read this same variable, they…1472) ==9090== by 0x6B0E0E9: buf_flush_write_block_low (buf0flu.c:999) ==9090== by 0x6B0EEC1: buf_…. Additionally, I’d consider backporting and using MySQL 5.5 atomic operation primitives with proper memory barriers,…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
…much load a given system can handle when load is low and we might not be able to perform reliable …to get CPU consumption per query ? You can take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql# cat /proc…31 0.99 # Bytes sent 8.77G 11 55.41M 5.15k 3.88k 258.55k 1.46k # Merge passes …
Post: How Innodb Contention may manifest itself
July 28, 2011 By 1 Comment
… though multiple fixes have been implemented in Percona Server and MySQL 5.5, there are still workloads in which case mutex (or rw… CPU will be very high, and the context switches will be somewhere reasonable. In others you would see the CPU usage being low with a lot of CPU being idle, increased compared to normal workload portion of system CPU and high…
Post: MySQL performance on EC2/EBS versus RDS
August 4, 2011 By 10 Comments
… what you can get on physical hardware, even low-to-medium sized servers. It’s not that …you’re limited in the number and speed of CPU cores you can get, and I/O performance …stock MySQL than it is to Percona Server. I haven’t run extensive benchmarks against RDS 5.5, Percona Server 5.5, and MySQL 5.5…
Post: Top 5 Wishes for MySQL
June 29, 2007 By 10 Comments
… is same as with MySQL Replication – the reason it is fast and has low performance overhead on … deny – MySQL does not handle complex queries well, being able to use only one CPU effectively … MySQL 5.0 without consistent work with MySQL close Partner – Innobase to ensure Group Commit still works in 5…
Post: MySQL Users Conference - Innodb
May 9, 2007 By 6 Comments
…ratio will not be good if it is too low there will be a lot of pages which …using multiple cores becomes increasingly important as their number per CPU just keeps doubling. It is also rather interesting …patch out where already which may come in MySQL 5.2 or even MySQL 5.1. I surely would like to see…
Post: Shard-Query adds parallelism to queries
November 15, 2010 By 16 Comments
…, workload and scalability: MySQL has always been focused on OLTP workloads. In fact, both Percona Server and MySQL 5.5.7rc have numerous performance…. On the other hand, MySQL 5.5.7 does not do this on its own. This is the low hanging fruit I was talking… increasing the number of workers past 24. The query becomes CPU bound at that point. If I needed more performance I…
Post: Predicting Performance improvements from memory increase
August 7, 2008 By 6 Comments
… way too much IO bound anyway. Interesting enough because of MySQL scaling issues it is also possible to see performance to… (high IO system utilization, low CPU usage) one should think about how much CPU capacity is available. If your CPU is 25% busy you… 100% IO subsystem utilization on 5% of CPU usage ? This is the true challenge becomes because MySQL has no tools to analyze working…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
… about transaction processing and all kinds of other things. In MySQL 5 number of Innodb performance counters were exported and now available…”. Spin locks are low cost wait, compared to OS wait, it is however active wait which wastes your CPU cycles, so if… 80157599, ACTIVE 5 sec, process no 3396, OS thread id 1150142816 fetching rows, thread declared inside InnoDB 166 mysql tables in use…
