There is a healthy discussion going on over in HADOOP-15566 on tracing in the Hadoop ecosystem. It would sit better on a mailing list than in comments up on JIRA so here's an attempt at porting the chat here.
Background/Context: Bits of Hadoop and HBase had Apache HTrace trace points added. HTrace was formerly "incubating" at Apache but has since been retired, moved to Apache Attic. HTrace and the efforts at instrumenting Hadoop wilted for want of attention/resourcing. Our Todd Lipcon noticed that the HTrace instrumentation can add friction on some code paths so can actually be harmful even when disabled. The natural follow-on is that we should rip out tracings of a "dead" project. This then beggars the question, should something replace it and if so what? This is where HADOOP-15566 is at currently. HTrace took two or three runs, led by various Heros, at building a trace lib for Hadoop (first). It was trying to build the trace lib, a store, and a visualizer. Always, it had a mechanism for dumping the traces out to external systems for storage and viewing (e.g. Zipkin). HTrace started when there was little else but the, you guessed it, Google paper that described the Dapper system they had internally. Since then, the world of tracing has come on in leaps and bounds with healthy alternatives, communities, and even commercialization. If interested, take a read over HADOOP-15566. Will try and encourage participants to move the chat here. Thanks, St.Ack --------------------------------------------------------------------- To unsubscribe, e-mail: common-dev-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-dev-h...@hadoop.apache.org
