Monthly Archives: September 2012

How to add new disk to FreeBSD

Posted by on September 12, 2012 No comments

We currently migrate all our projects to linux, but sometimes old FreeBSD issues occure.
Today I spend a couple of time, removing hotspare disk from LSI Megaraid and adding it to FBSD as additional disk.
We need quick solution to enhance disk space for couple of weeks for migration.
It was possible to skip failover and use disk without RAID.
So, Read more 🙂

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How I do mysql table aggregation.

Posted by on September 5, 2012 No comments

We have one huge old project with intensive mysql usage.
Due to some architectural errors, (sometimes development people do very strange things…) application continuously writes to several tables, partitioned by date. And they didn`t think about aggregation at all… Database growth very fast + 30 Gb per day. And it becomes real problem when we migrate data to SSD raid 10. (BTW it gives us 50 times performance boost!)
Our Application and reporting service doesn`t need such huge amount of data. Development of this project currently stalled, so only Operation team can do modifications.
I create archive database at slow SAS raid, and create aggregation sql. Main problem was – unknown partition number for data. There are 2 ways how to get it.

Use EXPLAIN PARTITIONS, and parse output, or just calculate number 🙂

How table was partitioned:

PARTITION BY HASH (TO_DAYS(`create_date`)) PARTITIONS 10

For Mysql 5.5
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