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From NOSQL to MySql (BDB to mysql) - Part2

So we are now in third week of Mysql deployment and slowly we are moving nodes from BDB to Mysql  Results so far have been promising.
1) We had ran into some query optimisation issues with Mysql that I blogged here http://neopatel.blogspot.com/2012/04/mysql-subquery-multiple-columns.html
2) Just ran into a 4 byte unicode issue with Mysql where utf8 with mysql wont support 4 bytes characters and apparently you have to use utf8mb4 for it, how stupid of Mysql.  Will write a separate blog post for it.

But as far as performance is concerned its rocking so far. On 20th we did the deployment and as soon as the node went live with Mysql you can see immediate drop in load avg consistently for this week. This is because most of the processing that was done by in memory db on app node is now transferred to Mysql.  But in second graph you would see that Mysql is sitting ducks and its no where close to app node load avg. Now this is with 3 nodes pounding, we would add 10+ nodes to start with on each Mysql and then consolidate later as I want to start conservative.

Biggest benefit we would  get is instead of managing 120+ BDBs on each node we would manage 10 Mysql servers and later we would even consolidate them once we see them sitting idle. I will share more details on sharding architecture I came up with in another blog post soon.
App Node Load Average
Mysql server load average


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Part5

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