Waffle Grid: More fast interconnect madness

So as I mentioned earlier I am seeing some rather odd behavior when I testing Waffle Grid and really fast interconnects.  In a nutshell, with faster access to pages it appears innodb does not need to throw items out of the buffer pool as often.  Test after test shows with Dolphin Fast interconnects I get outstanding performance, but they end up putting less into memcached ( LRU’s blocks ).  The same tests performed over and over on 1gbe, get a fraction of the performance but put 3x the data to memcached.  Looking at the numbers the fast interconnect tests all share a lower number of read aheads then the 1gbe test.   I was really leaning towards the read-ahead as the culprit.  So I commented out the read-ahead.  The result.  The same.  The 1gbe is now faster then before, but the dolphin interconnect tests still blow it out of the water, and does 1/4 of the sets to memcached then the 1gbe does.

Now don’t get me wrong the dolphin interconnect is fast, we are getting < 300 microsecond response times from it in our tests, while the 1gbe is around 1100 microseconds.  What is perplexing is why is less data being pushed out of innodb when I access disk faster?

The search goes on…

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One Response to Waffle Grid: More fast interconnect madness

  1. Matt says:

    Interesting, this waffle grid stuff sounds really cool, i can’t wait until this gets put to good use in future applications, it could be really huge.