*TL;DR*: The Analytics Hadoop cluster will be completely down for max
2h on *Feb
6th* (EU/CET morning) to upgrade all the daemons to Java 8.
Hi everybody,
we are planning to upgrade the Analytics Hadoop cluster to Java 8 on *Feb
6th* (EU/CET morning) for
https://phabricator.wikimedia.org/T166248.
Sadly we can't do a rolling upgrade of all the jvm-based Hadoop daemons
since the distribution that we use (Cloudera) suggests to perform the
upgrade only after a complete cluster shutdown. This means that for a
couple of hours (hopefully a lot less) all the Hadoop based services will
be unavailable (Hive, Oozie, HDFS, etc..).
We have tested the new configuration in labs and all the regular Analytics
jobs seem to work correctly, so we don't expect major issues after the
upgrade, but if you have any question or concern please follow up in the
task.
Thanks!
Luca and Andrew (on behalf of the Analytics team)