Sounds a lot like https://issues.apache.org/jira/browse/CASSANDRA-1123. The main change you'd want is to allow passing an external trace ID.
On Tue, Jun 14, 2011 at 3:57 PM, Ryan King <r...@twitter.com> wrote: > I'll open a ticket on this soon, but I'd like to start a discussion first. > > We're working on a distributed tracing system, whose design is > somewhat inspired by the Google Dapper paper [1]. We have instrumented > a bunch of our internal services through our custom networking stack > [2]. > > In a nutshell, the way it works is that each request is given a trace > id which gets passed through to each service involved in servicing > that request. Each hop in that tree is given a span id. Each node logs > its data to a local agent (we use scribe for this). An aggregator can > pull the pieces back together so you can do analysis. > > I'd like to add the ability to plug tracers into cassandra. Like with > many things in cassandra, I think like many parts of Cassandra we > should make this an extensible point with a good default > implementation in place. > > Here's what I propose: > > 1. Update the thrift server to allow clients to pass in tracing > details. I'll have docs soon on how we're doing this internally. > 2. Add the necessary metadata to each message passed between cassandra > nodes. This should be easy to Message.java and thread through to the > places we need it. > 3. Implement a universally useful version of this– one that's not > dependent on our system since it may not ever get open-sourced. > Perhaps writing to local files? > > Thoughts? Opinions? > > -ryan > > 1. http://research.google.com/pubs/pub36356.html > 2. https://github.com/twitter/finagle/tree/master/finagle-b3 > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com
