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From NOSQL to MySql (BDB to mysql) - Part5

This weekend was painful. Hardware came but out of 12 mysql servers, 3 had hardware issues, so only 8 mysql available (4 pair of Master-slave). I didn't wanted to take a risk of having a cluster up with only 1 master so left that one intentionally.

Started migration on 1st DC and after 4 hours the DC guys were doing some inbound network maintenance and took the in bound network to DC down and it took them 3 hours to restore it, so 3 hours were lost. We were up till 6:00 AM on Saturday morning and only able to finish 8-10 nodes.

We worked on Saturday night and as usual Berkely db gave us last minute jitters, one node was badly fragmented and took 10 hours to migration and one other node stuck in middle of migration so had to stop migration and run db_recovery and then resume again. In all 12-15 nodes migrated on that day.

We are now almost done 60% done in all DCs over last 3 weeks.

But all this pain is worth having a calm Monday where no system alerts or no Sales/Operations team hovering around you to diagnose scalability issues. This also in turn translates to better customer conversion and satisfaction.

Its first Monday in last few months where I had no single nagios alert raised for an app node spiking, hurray.



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