Solr Digest, June 2010
July 1, 2010 1 Comment
We have already written about news in Solr world this month here and here, so you already know that Solr’s 1.4.1. version was released, based on Lucene 2.9.3. Still, one thread from the mailing lists gives some more info about svn branches and how they are related to Solr versions.
Real Time indexing is again one of the hot topics. We already mentioned Zoie plugin in Solr March Digest, so this time we’ll point to interesting discussion on mailing lists. In case you followed this topic, Zoie Solr Plugin is a great plugin for Solr, but still has some limitations. For instance, master-slave architecture (which is the base of almost all big Solr deployments) isn’t well suited for Zoie. Version 2.9 of Lucene brought interesting addition of Near Realtime Search capabilities. As you probably already know, Solr 1.4 release already was running on Lucene 2.9 (2.9.1. to be precise), but support for NRT wasn’t implemented. Solr’s next release might have it since there is a JIRA issue dealing with NRT integration, but don’t hold your breath.
We’ll also mention some new functionalities in Solr:
- Added relevancy function queries – JIRA issue SOLR-1932 adds function queries for relevancy factors such as tf, idf, etc. This issue is already fixed and committed to trunk.
- Improved Solr response indentation – added with issue SOLR-1933. Solr only supported 7 levels of indenting previously, so this issue solves it. The downside is a small increase in response size (since instead of tabs, blank spaces will be used). The fix is already committed, but not only to trunk, but also to 3_x branch.
- Ever wanted to see index files without logging into your servers? This patch will make them visible from Solr admin pages or by using LukeRequestHandlers.
- Another related issue also got a patch and is already committed to the trunk – SOLR-1946 – misc enhancements to SystemInfoHandler. Here is a brief list of additions: include CWD in directory info, include raw bytes version of memory stats, include a list of all system properties.
We’ll end with the short overview of interesting issues which are still in development:
- Use Lucene’s Field Cache To Retrieve Stored Fields From Memory – the issue SOLR-1961 isn’t finished yet, althought there is a patch. When it is finished, it might give a new boost to the performance of your Solr server, thanks to developers from Cisco.
- If you want to track performance improvements prepared for 4.0 release, you can just follow JIRA issue SOLR-1965. Some stuff is already listed there, so you can go and check what is in store for the future versions.
- For anyone using PHP to talk to Solr, there is a new PHP Response Writer – currently, it is available as a Jar that has to be added to your Solr’s classpath. For more details check JIRA issue comments.
- Field collapsing is one of the longest still unresolved issues in Solr world. SOLR-236 (many people probably easily recognize this JIRA issue number :)) was created more than 3 years ago and during the time it has grown into a “monster” – huge number of comments, patches, problems, parameters… you name it. Integrating it with your Solr version was never fun (we tried it!). New hope appeared on the field collapsing horizon with the opening of SOLR-1682 (that’s a new JIRA issue for you to commit to your memory!). Some work had already been done there in the past, but now Yonik decided to dedicate some of his time to this issue, which means we might soon have a non-monster implementation that will be committed to Solr.
That’s all for this month. As you can see, in Solr May Digest there was no mention of new 1.4.1. release, but it happened, almost unexpectedly. So stay tuned (and follow @sematext) – you never know if something unexpected might happen this month too…