On 9/3/2014 8:14 PM, Li, Ryan wrote: > I have a Solr server indexes 2500 documents (up to 50MB each, ave 3MB) to > Solr server. When running on Solr 4.0 I managed to finish index in 3 hours. > > However after we upgrade to Solr 4.9, the index need 3 days to finish. > > I've done some profiling, numbers I get are: > size figure of document, time for adding to Solr server (4.0), time for > adding to Solr server (4.9) > 1.18, 6 sec, > 123 sec > 2.26 12sec > 444 sec > 3.35 18sec > over 600 sec > 9.65 46sec > timeout. > > From what I can see index seems has an o(n) performance for Solr 4.0 and is > almost o(log n) for Solr 4.9. I also tried to comment out some copied fields > to narrow down the problem, seems size of the document after index(we copy > fields and the more fields we copy, the bigger the index size is) is the > dominating factor for index time. > > Just wondering has any one experience similar problem? Does that sound like a > bug of Solr or just we have use Solr 4.9 wrong?
One possible source of problems with that particular upgrade is the fact that stored field compression was added in 4.1, and termvector compression was added in 4.2. They are on by default and cannot be turned off. The compression is typically fast, but with very large documents like yours, it might result in pretty major computational overhead. It can also require additional java heap, which ties into what follows: Another problem might be RAM-related. If your java heap is very large, or just a little bit too small, there can be major performance issues from garbage collection. Based on the fact that the earlier version performed well, a too-small heap is more likely than a very large heap. If your index size is such that it can't be effectively cached by the amount of total RAM on the machine (minus the java heap assigned to Solr), that can cause performance problems. Your index size is likely to be several gigabytes, and might even reach double-digit gigabytes. Can you relate those numbers -- index size, java heap size, and total system RAM? If you can, it would also be a good idea to share your solrconfig.xml. Here's a wiki page that goes into more detail about possible performance issues. It doesn't mention the possible compression problem: http://wiki.apache.org/solr/SolrPerformanceProblems Thanks, Shawn
