Historical will drop a segment that shouldn't be dropped in the following scenario:
Historical node tried to load segmentA, but failed with SegmentLoadingException,
then ZkCoordinator called removeSegment(segmentA, blah) to schedule a runnable that would drop segmentA by deleting its files. Now, before that runnable executed, another LOAD request was sent to this historical, this time historical actually succeeded on loading segmentA and announced it. But later on, the scheduled drop-of-segment runnable started executing and removed the segment files, while historical is still announcing segmentA.
`insert-segment-to-db` is a tool that can insert segments into Druid metadata storage. It is intended to be used
to update the segment table in metadata storage after people manually migrate segments from one place to another.
It can also be used to insert missing segment into Druid, or even recover metadata storage by telling it where the
segments are stored.
Note: This tool expects users to have Druid cluster running in a "safe" mode, where there are no active tasks to interfere
the segments being inserted. Users can optionally bring down the cluster to make 100% sure nothing is interfering.
- fixes#1970
- extracted out segment handoff callbacks in SegmentHandoffNotifier
which is responsible for tracking segment handoffs and doing callbacks
when handoff is complete.
- Coordinator now maintains a view of segments in the cluster, this
will affect the jam heap requirements for the overlord for large
clusters.
realtime index task and nodes now use HTTP end points exposed by the
coordinator to get serverView
review comment
fix realtime node guide injection
review comments
make test not rely on scheduled exec
fix compilation
fix import
review comment
introduce immutableSegmentLoadInfo
fix son reading
remove unnecessary logging
This is a feature meant to allow realtime tasks to work without being told upfront
what shardSpec they should use (so we can potentially publish a variable number
of segments per interval).
The idea is that there is a "pendingSegments" table in the metadata store that
tracks allocated segments. Each one has a segment id (the same segment id we know
and love) and is also part of a sequence.
The sequences are an idea from @cheddar that offers a way of doing replication.
If there are N tasks reading exactly the same data with exactly the same logic
(think Kafka tasks reading a fixed range of offsets) then you can place them
in the same sequence, and they will generate the same sequence of segments.
1) Remove maven client from downloading extensions at runtime.
2) Provide a way to load Druid extensions and hadoop dependencies through file system.
3) Refactor pull-deps so that it can download extensions into extension directories.
4) Add documents on how to use this new extension loading mechanism.
5) Change the way how Druid tarball is generated. Now all the extensions + hadoop-client 2.3.0
are packaged within the Druid tarball.
- move assembly out of druid-services into a 'distribution' module
- create separate 'extensions-distribution' module and assembly to
package extensions and their dependencies into a local maven
repository
- include this extensions maven repository in the binaries tarball
Nishant
Charles Allen
Himanshu
Bingkun Guo
Navis Ryu
Xavier Léauté
Fangjin Yang
Parag Jain
Xavier Léauté
Gian Merlino
Bartosz Ługowski