public void proceedCommandExecution() {
// Steps are executed such that:
// a) all logic before the command runs is idempotent
// b) the command is the last action in the step
// This allows for recovery after a crash at any point during command execution.
log.debug("Proceeding with execution of RemoveSnapshotSingleDiskLiveCommand");
if (getParameters().getCommandStep() == null) {
getParameters().setCommandStep(getInitialMergeStepForImage(getParameters().getImageId()));
getParameters().setChildCommands(new HashMap<RemoveSnapshotSingleDiskLiveStep, Guid>());
}
// Upon recovery or after invoking a new child command, our map may be missing an entry
syncChildCommandList();
Guid currentChildId = getCurrentChildId();
VdcReturnValueBase vdcReturnValue = null;
if (currentChildId != null) {
switch (CommandCoordinatorUtil.getCommandStatus(currentChildId)) {
case ACTIVE:
case NOT_STARTED:
log.info(
"Waiting on Live Merge command step '{}' to complete",
getParameters().getCommandStep());
return;
case SUCCEEDED:
CommandEntity cmdEntity = CommandCoordinatorUtil.getCommandEntity(currentChildId);
if (cmdEntity.isCallbackEnabled() && !cmdEntity.isCallbackNotified()) {
log.info(
"Waiting on Live Merge command step '{}' to finalize",
getParameters().getCommandStep());
return;
}
vdcReturnValue = CommandCoordinatorUtil.getCommandReturnValue(currentChildId);
if (vdcReturnValue != null && vdcReturnValue.getSucceeded()) {
log.debug("Child command '{}' succeeded", getParameters().getCommandStep());
getParameters().setCommandStep(getParameters().getNextCommandStep());
break;
} else {
log.error(
"Child command '{}' failed: {}",
getParameters().getCommandStep(),
(vdcReturnValue != null
? vdcReturnValue.getExecuteFailedMessages()
: "null return value"));
setCommandStatus(CommandStatus.FAILED);
return;
}
case FAILED:
case FAILED_RESTARTED:
log.error("Failed child command status for step '{}'", getParameters().getCommandStep());
setCommandStatus(CommandStatus.FAILED);
return;
case UNKNOWN:
log.error("Unknown child command status for step '{}'", getParameters().getCommandStep());
setCommandStatus(CommandStatus.FAILED);
return;
}
}
log.info("Executing Live Merge command step '{}'", getParameters().getCommandStep());
Pair<VdcActionType, ? extends VdcActionParametersBase> nextCommand = null;
switch (getParameters().getCommandStep()) {
case EXTEND:
nextCommand = new Pair<>(VdcActionType.MergeExtend, buildMergeParameters());
getParameters().setNextCommandStep(RemoveSnapshotSingleDiskLiveStep.MERGE);
break;
case MERGE:
nextCommand = new Pair<>(VdcActionType.Merge, buildMergeParameters());
getParameters().setNextCommandStep(RemoveSnapshotSingleDiskLiveStep.MERGE_STATUS);
break;
case MERGE_STATUS:
getParameters().setMergeCommandComplete(true);
nextCommand = new Pair<>(VdcActionType.MergeStatus, buildMergeParameters());
getParameters().setNextCommandStep(RemoveSnapshotSingleDiskLiveStep.DESTROY_IMAGE);
break;
case DESTROY_IMAGE:
if (vdcReturnValue != null) {
getParameters()
.setMergeStatusReturnValue(
(MergeStatusReturnValue) vdcReturnValue.getActionReturnValue());
} else if (getParameters().getMergeStatusReturnValue() == null) {
// If the images were already merged, just add the orphaned image
getParameters().setMergeStatusReturnValue(synthesizeMergeStatusReturnValue());
}
nextCommand = new Pair<>(VdcActionType.DestroyImage, buildDestroyImageParameters());
getParameters().setNextCommandStep(RemoveSnapshotSingleDiskLiveStep.COMPLETE);
break;
case COMPLETE:
getParameters().setDestroyImageCommandComplete(true);
setCommandStatus(CommandStatus.SUCCEEDED);
break;
}
persistCommand(getParameters().getParentCommand(), true);
if (nextCommand != null) {
CommandCoordinatorUtil.executeAsyncCommand(
nextCommand.getFirst(), nextCommand.getSecond(), cloneContextAndDetachFromParent());
// Add the child, but wait, it's a race! child will start, task may spawn, get polled, and we
// won't have the child id
}
}
