With the release of Solr 4.2 we’ve got the possibility to use the HTTP protocol to get information about Solr index structure. Of course, if one wanted to do that prior to Solr 4.2 it could be achieved by fetching the schema.xml file, parsing it and then getting the needed information. However when Solr 4.2 was released we’ve got a dedicated API which can return the information we need without the need of parsing the whole schema.xml file.
Did you ever wonder if you can create a backup of your index with the tools available in Solr ? For exmaple after every commit or optimize operation ? Or may you would like to create backups with the HTTP API call ? Lets see what possibilities Solr has to offer.
Imagine the following problem – we have an application that expects Solr to return the results sorted on the basis of some field. Those results will be than paged in the GUI. However, if the person using the GUI application immediately selects the tenth, twentieth, or fiftieth page of search results there is a problem – the wait time. Is there anything we can do about this? Yes, we can help Solr a bit.
From time to time, in working with Solr there is a problem – how to update Solr index structure. There are various reasons for these changes – the new functional requirements, optimization, or anything else – it is not important. What is important is the question that arise – should we remove the index, or simply change the structure and do a full indexing? Contrary to appearances, the answer to this question depends on the changes we made in the structure of the index.
While using Lucene and Solr we are used to a very high reliability of this products. However, there may come the day when Solr will inform us that our index is corrupted, and we need to do something about it. Is the only way to repair the index is to restore it from the backup or do full indexation ? Not only – there is hope in the form of CheckIndex tool.
At the Apache Lucene Eurocon 2010 conference, which took place in May this year, Andrew Białecki in his presentation talked about how to obtain satisfactory search results when using early termination search techniques. Unfortunately the tool he mentioned, was not available in Solr – but it changed.
I made a promise and here it is – the entry on the most common mistakes when designing Solr index, which is when You create or modify the schema.xml file for Your system implementation. Feel free to read on 😉