Currently, we have a lot of uses for drizzledump + restore:  upgrading Drizzle, backing up data, etc.  Since we are putting people in a position to rely on these tools, it seemed prudent that we improve our testing in this area.

Our plan was to include both test-suite tests as well as more vigorous testing with the randgen.  The test-suite tests are pretty straightforward and are in tests/t/drizzledump_restore.test.  You can get Drizzle here to check them out if reading test cases is your idea of fun : )  Of course, the randgen tests are the ones that do the interesting, high-volume stuff.

In a nutshell, the randgen test randomly generates any number of test tables in a database. The test tables have random composition (columns and datatypes used) and data population.  Once the tables have been generated, we call drizzledump, restore the tables from the dump file to a new database, then do a table-to-table comparison of the original and restored tables.  We report error and debugging information if we find a difference, and go on our happy way otherwise.

This test is now a part of our regular build and test system and runs on every push to trunk.  We make use of a standard, repeatable set of queries and we also make use of the randgen’s ability to randomize data and queries and use –seed=time for a smaller run of the same test.  This gives us a larger spread of tests each run.  Fortunately, the randgen is nice enough to report the seed value for repeatability in case we encounter a bug.

Feeding the randgen the same seed value for a grammar / gendata file combination will produce the same tables, data, and queries each time.

I’m happy to report that the test currently passes with flying colors.  Interestingly enough, I discovered what happens when you try to have several clients running drizzledump, creating and altering test tables, and restoring data from dumpfiles and it isn’t pretty.  Please note that our test is designed to run with only a single thread at a time : )

If anyone is interested in testing or anything else related to Drizzle, stop by IRC (#drizzle) or drop us a line on our mailing list.