RediSearch

Sphinx is an open source full text search server, designed from the ground up with performance, relevance (aka search quality), and integration simplicity in mind. It's written in C++ and works on Linux (RedHat, Ubuntu, etc), Windows, MacOS, Solaris, FreeBSD, and a few other systems. Sphinx lets you either batch index and search data stored in an SQL database, NoSQL storage, or just files quickly and easily, or index and search data on the fly, working with Sphinx pretty much as with a database server. A variety of text processing features enable fine-tuning Sphinx for your particular application requirements, and a number of relevance functions ensures you can tweak search quality as well. Searching via SphinxAPI is as simple as 3 lines of code, and querying via SphinxQL is even simpler, with search queries expressed in good old SQL. Sphinx indexes up to 10-15 MB of text per second per single CPU core, that is 60+ MB/sec per server (on a dedicated indexing machine).

Livegrep is a tool, partially inspired by Google Code Search, for interactive regex search of ~gigabyte-scale source repositories. To run livegrep, you need to invoke both the codesearch backend index/search process, and the livegrep web interface. To run the sample web interface over livegrep itself, once you have built both codesearch and livegrep. The codesearch binary is responsible for reading source code, maintaining an index, and handling searches. livegrep is stateless and relies only on the connection to codesearch over a TCP connection. By default, codesearch will build an in-memory index over the repositories specified in its configuration file. You can, however, also instruct it to save the index to a file on disk. This has the dual advantages of allowing indexes that are too large to fit in RAM, and of allowing an index file to be reused.