… or certain times. Investigating them we find out what the cause is some batch jobs, reports and other non response time critical activities… need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing… you put too heavy of concurrent load on it the response times will increase and user experience will suffer. So what you…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
… certain times which I may be able to correlate to some events ? If you can’t get fancy … easier to understand which of the applications were responsible for memory allocation. If you figured out it … you can do better as you can query temporary tables too: mysql> select sum(data_length+index_length) …
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
… row in set (0.03 sec) Notice the difference in response time. Refresh method performance comparison For demonstration purposes, I did the… about of time: mysql> call flexviews.enable( -> flexviews.get_id(‘demo’,'complete_example2′)); Query OK, 0 rows affected (42 min 42.14 sec) mysql> call…
Post: What do we optimize with mk-query-digest ?
December 15, 2009 By 2 Comments
… is however perfectly possible to get bad performance with MySQL responsible for large portion of response time without any slow queries. We’ve seen pages which take 10.000, 20.000 and even more queries…
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… from 1988 to 2010′; mysql> use ontime1; Database changed mysql> show table status like ‘ontime_…query response times and throughput. Setting up a cluster using the AMI images You can easily test Shard-Query…-length=16K #we value throughput over response time, get a good plan optimizer-prune-level=…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 22 Comments
…Query over Hive is that it works with existing MySQL data sets and queries. Another advantage is that it works with all MySQL…queries, followed by a response time table recording the actual response times for each query. The queries…
Post: Reasons for MySQL Replication Lag
July 29, 2011 By 6 Comments
… causing replication to lag. Failed hard drive getting RAID in degraded mode could be one common…see it as higher IO load (IO utilization, response time) while less work is being done in … which queries mysql. I’ve seen monitoring updates which would add excessively expensive and frequent query on …
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…MySQL. This is very helpful for measurement as otherwise we might not catch some long running connections. Now let’s get…of the output produced by pt-query-digest. # Profile # Rank Query ID Response time Calls R/Call Apdx V/M Item # ==== ================== ============= ===== ====== ==== ===== …
Post: Should we give a MySQL Query Cache a second chance ?
April 10, 2011 By 63 Comments
… all queries have to be invalidated from the query cache… which can take a lot of time if you have millions of queries cache…. Improve Manageability What is in the MySQL Query Cache ? How many hits did we get for this query item ? Right now none of such… INFORMATION_SCHEMA tables. Self Refresh MySQL Query Cache causes not uniform performance as you get very fast responses for hits but you might need…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
… aggregate functions. The results from this aggregation get a second distributed reduce using UPSERTs into … center B and distribute the queries over both data centers. The response time should only be increased … which speaks SQL, but right now only MySQL storage nodes are supported. Amdahl’s law …
