ramkrishna.s.vasudevan created HBASE-19017:
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Summary: EnableTableProcedure is not retaining the assignments
Key: HBASE-19017
URL: https://issues.apache.org/jira/browse/HBASE-19017
Project: HBase
Issue Type: Bug
Components: Region Assignment
Affects Versions: 2.0.0-alpha-3
Reporter: ramkrishna.s.vasudevan
Assignee: ramkrishna.s.vasudevan
Fix For: 2.0.0-beta-1
Found this while working on HBASE-18946. In branch-1.4 when ever we do enable
table we try retain assignment.
But in branch-2 and trunk the EnableTableProcedure tries to get the location
from the existing regionNode. It always returns null because while doing region
CLOSE while disabling a table, the regionNode's 'regionLocation' is made NULL
but the 'lastNode' is actually having the servername where the region was
hosted. But on trying assignment again we try to see what was the last
RegionLocation and not the 'lastNode' and we go ahead with new assignment.
On region CLOSE while disable table
{code}
public void markRegionAsClosed(final RegionStateNode regionNode) throws
IOException {
final RegionInfo hri = regionNode.getRegionInfo();
synchronized (regionNode) {
State state = regionNode.transitionState(State.CLOSED,
RegionStates.STATES_EXPECTED_ON_CLOSE);
regionStates.removeRegionFromServer(regionNode.getRegionLocation(),
regionNode);
regionNode.setLastHost(regionNode.getRegionLocation());
regionNode.setRegionLocation(null);
regionStateStore.updateRegionLocation(regionNode.getRegionInfo(), state,
regionNode.getRegionLocation()/*null*/, regionNode.getLastHost(),
HConstants.NO_SEQNUM, regionNode.getProcedure().getProcId());
sendRegionClosedNotification(hri);
}
{code}
In AssignProcedure
{code}
ServerName lastRegionLocation = regionNode.offline();
{code}
{code}
public ServerName setRegionLocation(final ServerName serverName) {
ServerName lastRegionLocation = this.regionLocation;
if (LOG.isTraceEnabled() && serverName == null) {
LOG.trace("Tracking when we are set to null " + this, new
Throwable("TRACE"));
}
this.regionLocation = serverName;
this.lastUpdate = EnvironmentEdgeManager.currentTime();
return lastRegionLocation;
}
{code}
So further code in AssignProcedure
{code}
boolean retain = false;
if (!forceNewPlan) {
if (this.targetServer != null) {
retain = targetServer.equals(lastRegionLocation);
regionNode.setRegionLocation(targetServer);
} else {
if (lastRegionLocation != null) {
// Try and keep the location we had before we offlined.
retain = true;
regionNode.setRegionLocation(lastRegionLocation);
}
}
}
{code}
Tries to do retainAssignment but fails because lastRegionLocation is always
null.
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