…response time. As a result we measure 95% or 99% response times. What does it give to us? It allows to see: What is the response time…server. For example, the famous problem with DROP TABLE performance. Does DROP TABLE, running in separate session, affect a response time…
Post: Introducing tcprstat, a TCP response time tool
August 31, 2010 By 12 Comments
…? In a nutshell, it is a lightweight way to measure response times on a server such as a database, memcached, Apache, and so on… information about the response time of the requests within that time period. Here “response time” means, for a given TCP connection, the time elapsed from the… simple protocols such as HTTP and MySQL, this is the moral equivalent of a query’s response time. The statistics we chose to…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…Server is the ability to enable logging atomically, not just for new connections as in MySQL. This is very helpful for measurement…MySQL server, you would see an entry like this in the slow query log: # Time… Rank Query ID Response time Calls R/Call Apdx V/M Item # ==== ================== …
Post: Is your MySQL Server Loaded ?
March 19, 2010 By 4 Comments
…benchmark/stress test – how do you tell if MySQL server is really loaded ? This looks like the …connections) – but you can see most of the time it is less than that. Looking at …Server side. The server has gotten the query but has not completed sending response back yet. This is a very broad measure…
Post: The two even more fundamental performance metrics
May 5, 2011 By 6 Comments
… distribution of service times. Service time is not the same as response time, which includes time spent waiting in the queue. If you measure a period… the typical response time is under a millisecond — maybe it’s 50 microseconds, maybe a bit longer. This is common in MySQL servers I…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
… how much time each buffer hit or miss takes. If you approach application performance optimization from the standpoint of response time measurements, which you…. The reality is that this server setting is very subjective, and there is no good instrumentation in MySQL to guide your decisions…
Post: Why message queues and offline processing are so important
August 10, 2010 By 3 Comments
… here: Response Time – This is the time required to complete a desired task. Throughput – Throughput is measured in tasks completed per unit of time. Capacity… queue, or Gearman. Or in plain English: The same MySQL servers can achieve much more work, if you allow the potential…
Post: How to Identify Bad Queries in MySQL
January 10, 2011 By 16 Comments
…that they aren’t optimal. A responsible approach to a task such as…at what the server is doing. For example, in Percona Server we have microsecond…for, which has been available in MySQL for years. This is necessary … done it many times with simple awk scripts and various statistical measures. What do …
Comment: Introducing tcprstat, a TCP response time tool
September 12, 2010 By 12 Comments
… measurement of the query response time, you have to do it in the database server itself (i.e. use the slow query log in MySQL), because even measuring… you no longer know the difference between the network time and the query response time. This is one reason why tcprstat has the…
Post: Goal driven performance optimization
December 22, 2008 By Leave a Comment
…images uploaded and measure the response time for them specifically …response time of the problematic pages: mysql> select count(*),avg(wtime),avg(utime/wtime) cpu_ratio, avg(mysql_time/wtime) mysql_ratio ,avg(sphinx_time…MySQL server application there is often the question if it is MySQL server…
