MySQL Cluster Performance Tuning
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In this session we will look at different tuning aspects of MySQL Cluster.
As well as going through performance tuning basics in MySQL Cluster, we will look closely at the new parameters and status variables of MySQL Cluster 7.2 to determine issues with e.g disk data performance and query (join) performance.
This was the last session I attend, and for me is alway a great pleasure to be at Johan presentations, for many reasons:
- he is probably the best cluster expert (in service delivery)
- he knows a lot of distinctiveness and insight that no one else knows
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Speech taken by Johan "my Viking" Andersson
MySQL/Oracle has released a new version of MySQL cluster recently, and I had the opportunity to test a little bit but not really in depth as I would like.
But one of the aspect that I was looking for what the way how the "condition pushdown" was modified.
Johan confirm by tests (empiric is always more trustable then commercial announcements), the way it is working now. NDBcluster returns the full result set, no sub set to MySQL and additional requests, so less roundtrip, and the relations by ID are resolved at local data node level.
Interesting the way it is also possible to partition data by Key associating that on the Data node, that would increase the locality of reference also if not implementing a real partition pruning.
Only negative note is that we still have the annoying problem with the MySQL SQL node/connection pool, it is still taking 1 slot out of the 253 available for each connection in the pool. This means that if I have 4 MySQL SQL nodes each allocating 10 connection in the pool, I will take out 40 connections from the 253, instead 4.
This cannot be a problem, but given I have done several MySQL cluster implementations, I can say that when MySQL is really used it needs to heave a huge number of Data nodes and MySQL nodes, resulting to a very high number of connections slot used.
References