I've ran into a strange bug where get_slice returns the result from previous query. My application iterates over a set of columns inside a supercolumn and for some reason it sometimes (quite rarely but often enough that it shows up) the results gets "shifted" around so that the application gets the previous result. The application is using the same cassandra thrift connection (it doesn't close it in between) and everything is happening inside same php process.
Here's a cleaned up example from logs where this happens: 14:40 suomirock php-fi: [MISC] WARNING /blog.php: Cassandra stored blog content for blog id 47528165 differs from database content. 14:40 suomirock php-fi: [MISC] WARNING /blog.php: from cassandra: AAAAAAAA 14:40 suomirock php-fi: [MISC] WARNING /blog.php: from database : BBBBBBBBB 14:40 suomirock php-fi: [MISC] WARNING /blog.php: Cassandra stored blog content for blog id 47523032 differs from database content. 14:40 suomirock php-fi: [MISC] WARNING /blog.php: from cassandra: BBBBBBBBB 14:40 suomirock php-fi: [MISC] WARNING /blog.php: from database : CCCCCCCCCC The data model is that I have a Super Column family which stores blog entries. Each user has a single row. Inside this row there are CF's where each CF contains a single blog entry. The key of the CF is the blog id number and one of the columns inside the CF contains the blog content. The data which is in cassandra is correctly there and it's the same what's inside our old storage tier (PostgreSQL) so I'm able to compare the data returned from cassandra with the data returned from old database. Here's part of the output from cassandra-cli where I queried the row for this user. As you can see, the "blog id" matches the super_column inside cassandra. => (super_column=47540671, (column=content, value=AAAAAAAA, timestamp=1282940401925456) ) => (super_column=47528165, (column=content, value=BBBBBBBBB, timestamp=1282940401925456) ) => (super_column=47523032, (column=content, value=CCCCCCCCCC, timestamp=1282940401925456) ) I'm in the middle of writing bunch of debugging code to get better data what's really going on, but I'd be very happy if someone could have any clue or helpful ideas how to debug this out. - Juho Mäkinen
