Hi there We are currently upgrading from solr 1.4 to 3.4 and have seen some issues with our specific use-case. As background we drop the whole index and then add all our documents in one big build before we commit and then optimise. This way we can revert the build if there are any issues and this won't be replicated out to our slave instances.
We use the following flags: -Xmx2g -Xms2g With 1.4 it works pretty well, and the process doesn't use much more than 2GB of memory as the index is being built. Garbage collector kicks in quite a bit but performance are pretty decent throughout the build. For 3.4 though the process builds up to use a lot more memory, about 20 to 30 GB and it starts swapping and grinding to a bit of a halt. This means it takes about 10 times longer to complete the build, but it does complete. We have about a 100k documents and they aren't massive, but they aren't small either. They do have a lot of fields though, some have 6000+ fields. Monitoring the heap size I can see that it stays under 2GB and garbage collector seems to kick in just like with 1.4 While we could increase the memory and do a few other things to make this less of an issue I would really like to know if anyone has any idea what the problem could be and what we could do to try and change the behaviour in config. Our solrconfig.xml file is the same for 1.4 and 3.4, we haven't made any changes. Thanks Willem Basson
