Welcome to the list Pinney :) On Aug 30, 2012, at 10:59 AM, Pinney Colton <pinney.col...@bitwisedata.com> wrote:
> Hi all - > > This is my first post to the list. I'm a relative Riak newbie, though I have > some experience working with multi-terabyte datasets on other platforms. > Last night, I kicked off my first "large" load of data as a test of the > platform with about 1,000,000 json objects being loaded into a bucket. I had > a couple performance issues, so I'm wondering if someone on the list could be > kind enough to answer a few questions that will help me troubleshoot. > > a) I haven't analyzed all of my load log data yet, but it look like writes > went from about 0.02 seconds per object to a couple minutes per object! This > is the typical "dev" setup from the tutorials, and I forgot to divide > available RAM by 4 to arrive at a number per node - is this likely the result > of a memory constraint, or should I be looking elsewhere, beyond just bumping > the memory on my VM? I looked at the logs, but I'm not sure what I should be > looking for. I'm wondering if you're starting to swap. Have you set swappiness to 0 on the machine? If not, I'd recommend that change. > > b) I am using protocol buffers, and I saw similar initial performance when > running the load from a separate machine vs. having the data on the riak > machine itself. Is that what you would recommend? I'm wondering if there is > any hard/fast rule re: CPU/Memory contention on the machine vs. network > performance of loading from a different machine. I don't think there is a hard and fast rule here, but I would try doing it over the network rather than on the same node. > > c) I'm using a sha256 hash as my bucket name. I read that buckets and keys > are concatenated internally and that all objects have just one "bucketkey". > Am I putting significantly more pressure on memory by using such a long > bucket name? Or is Riak managing that for me via some sort of compression? > If that long hash is being replicated for each of those million objects, I > can see where my memory estimates would have been low. I can always use an > integer ID for my bucket name, the hash just existed elsewhere in my > application, so I used it without thinking about it too much. This depends on the backend you use. Bitcask holds all bucket/keys in memory, so their size is important. Leveldb doesn't have this constraint, and even has key prefix compression. > > Thanks in advance for your help! Loving Riak so far, in spite of these > trivial hurdles. > > Regards, > Pinney > > _______________________________________________ > riak-users mailing list > riak-users@lists.basho.com > http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com _______________________________________________ riak-users mailing list riak-users@lists.basho.com http://lists.basho.com/mailman/listinfo/riak-users_lists.basho.com
