The RS already returns to the client whether or not it has additional
results to be returned in a subsequent call to scan(), but the ClientScanner
did not use or adhere to this value. Subsequently, this can lead to
bugs around moving to the next region too early. A new method was added
to ClientScanner in the name of testability.
Encapsulate server-state into RegionServerCallable to avoid
modifying parameterization of callable impls.
Signed-off-by: Andrew Purtell <apurtell@apache.org>
Include some basic tests for the method on a testing cluster.
Also update master page to show an alert when balancer is disabled.
Signed-off-by: Enis Soztutar <enis@apache.org>
Summary:
The current behavior of a region move shuts down a region and then starts is up in another regionserver. This causes increased latency and possibly timeouts till the new region's cache is fully warmed up. We can make a region move less disruptive by warming the cache in the destination region server before shutting dow the old region.
See https://issues.apache.org/jira/browse/HBASE-13316
Test Plan:
1. Unit Tests
2. Added test for concurrent moves and warmups
3. Manually tested reads/writes happening with concurrent moves
Subscribers: tedyu
Differential Revision: https://reviews.facebook.net/D35967
Signed-off-by: Elliott Clark <eclark@apache.org>
Instead of just blocking the client for 90 seconds when the region gets too
busy, it now sends along region load stats to the client so the client can
know how busy the server is. Currently, its just the load on the memstore, but
it can be extended for other stats (e.g. cpu, general memory, etc.).
It is then up to the client to decide if it wants to listen to these stats.
By default, the client ignores the stats, but it can easily be toggled to the
built-in exponential back-off or users can plug in their own back-off
implementations
Summary: This is a follow up diff for the jira to add the functionality to update configs in an online fashion.
Test Plan: Unit test. This adds an end point on the regionserver. It just tries to call the end point and make sure the call succeeds.
Differential Revision: https://reviews.facebook.net/D24861
Signed-off-by: stack <stack@apache.org>
