It is quite common to use this approach when load-testing webservers. It just makes sens to apply it to … account (size of data set, usage of persistent connection) – and there are even more in web benchmarking: how long does a user wait… with compressed content, etc… This is way every real-life load test is in fact a project by itself – and why…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…), because the query was taking far too long to execute, ~11 hours in case … so that the relevant pages were already loaded in the buffer pool. Note that …1.53G 1.89G 1.53G Innodb_data_reads 120552 123872 100551 103011 77213 …_read_key. This is because of how status counter values are incremented when …
Post: Predicting how long data load would take
May 24, 2007 By 12 Comments
… data load goes I usually tend to do something like “du -sh; sleep 3600; du -sh” in the database data directory to see how… data load speed of 60GB during one hour and 10GB during another depending on the tables which were loaded. During our recent data load we loaded… memory) plus we loaded data in parallel and our rows were relatively long. In most cases I would expect load speed to be a…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…’s impossible to predict. A customer may call and ask “how long to debug server lockups?” It could be ten minutes, or… at the data in the server and see what I think about it. If the server is not heavily loaded, I may… and so forth. If the server is heavily loaded or has a lot of data, touching the INFORMATION_SCHEMA can take a…
Post: How to load large files safely into InnoDB with LOAD DATA INFILE
July 3, 2008 By 28 Comments
… customer ask me about loading two huge files into InnoDB with LOAD DATA INFILE. The goal was to load this data on many servers without putting it into the binary log. While this is generally a fast way to load data… and the load needs to roll back, it will take a Very Long Time to do — I hate to think how long. I’m…
Post: How to estimate time it takes Innodb to Recover ?
May 9, 2007 By 7 Comments
… second. Database Size This comes back to the data locality but with same data access distribution the larger database you’ll have… on systems with large number of hard drives. So how do you estimate how long it takes Innodb to Recover ? Now you know… some benchmarks – apply the load you expect system to handle and crash Innodb few times to see how long it takes Innodb to…
Post: How much overhead is caused by on disk temporary tables
August 16, 2007 By 26 Comments
… to perform them anyway which can cause IO bound load even with small data which can fully fit in OS cache as…_writes | 185808 | +————————+———+ 7 rows in set (0.00 sec) So how long does it take: mysql> select count(*) cnt,c from gt… may not scale proportionally with table size, even when all data fits in memory MEMORY temporary tables can be 10-100…
Post: How expensive is MySQL Replication for the Master
January 16, 2010 By 13 Comments
… on Master, depending on number of Slaves. What kind of load extra Slave causes ? Well it just gets a copy of… some auto detection in place timing how long it really takes all threads to send their data to the slave. If you have… this case teach me in general ? To always look for data rather and question your assumptions. If something is unlikely to…
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
… and application is suffering because of stale data. This especially applies to Software as Service …”cold” vs “hot” replication capacity as well as how long replication warmup takes. It is very typical … the peak load and 5 during the normal load. This applies to normal operational load – if you …
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… measurement as otherwise we might not catch some long running connections. Now let’s get started. Before … 213 0.0003 1.00 0.00 SELECT data_template_rrd data_input_fields # 16 0xBE797E1DD5E4222F 0.0524 0.6…the output the # MISC part, it tells you how much of “load” is not covered by top queries, we …
