private long getCommitTimestampRollBackIfNecessary(
long startTimestamp, Multimap<String, Cell> tableNameToCell) {
Long commitTimestamp = transactionService.get(startTimestamp);
if (commitTimestamp == null) {
// Roll back this transaction (note that rolling back arbitrary transactions
// can never cause correctness issues, only liveness issues)
try {
transactionService.putUnlessExists(startTimestamp, TransactionConstants.FAILED_COMMIT_TS);
} catch (KeyAlreadyExistsException e) {
String msg =
"Could not roll back transaction with start timestamp "
+ startTimestamp
+ "; either"
+ " it was already rolled back (by a different transaction), or it committed successfully"
+ " before we could roll it back.";
log.error(
"This isn't a bug but it should be very infrequent. " + msg,
new TransactionFailedRetriableException(msg, e));
}
commitTimestamp = transactionService.get(startTimestamp);
}
if (commitTimestamp == null) {
throw new RuntimeException(
"expected commit timestamp to be non-null for startTs: " + startTimestamp);
}
if (commitTimestamp == TransactionConstants.FAILED_COMMIT_TS) {
for (String table : tableNameToCell.keySet()) {
Map<Cell, Long> toDelete =
Maps2.createConstantValueMap(tableNameToCell.get(table), startTimestamp);
keyValueService.delete(table, Multimaps.forMap(toDelete));
}
}
return commitTimestamp;
}
private long ensureCommitTimestampExists(
Long startTs, @Modified Map<Long, Long> startTsToCommitTs) {
Long commitTs = startTsToCommitTs.get(startTs);
if (commitTs == null) {
// Roll back this transaction (note that rolling back arbitrary transactions
// can never cause correctness issues, only liveness issues)
try {
// TODO: carrino: use the batched version of putUnlessExists when it is available.
transactionService.putUnlessExists(startTs, TransactionConstants.FAILED_COMMIT_TS);
} catch (KeyAlreadyExistsException e) {
String msg =
"Could not roll back transaction with start timestamp "
+ startTs
+ "; either"
+ " it was already rolled back (by a different transaction), or it committed successfully"
+ " before we could roll it back.";
log.error(
"This isn't a bug but it should be very infrequent. " + msg,
new TransactionFailedRetriableException(msg, e));
}
commitTs = transactionService.get(startTs);
Validate.notNull(commitTs);
startTsToCommitTs.put(startTs, commitTs);
}
return commitTs;
}
private Multimap<Cell, Long> getCellTsPairsToSweep(
Multimap<Cell, Long> cellTsMappings,
PeekingIterator<RowResult<Value>> values,
long sweepTimestamp,
SweepStrategy sweepStrategy,
@Output Set<Cell> sentinelsToAdd) {
Multimap<Cell, Long> cellTsMappingsToSweep = HashMultimap.create();
Map<Long, Long> startTsToCommitTs = transactionService.get(cellTsMappings.values());
for (Map.Entry<Cell, Collection<Long>> entry : cellTsMappings.asMap().entrySet()) {
Cell cell = entry.getKey();
Collection<Long> timestamps = entry.getValue();
boolean sweepLastCommitted = isLatestValueEmpty(cell, values);
Iterable<? extends Long> timestampsToSweep =
getTimestampsToSweep(
cell,
timestamps,
startTsToCommitTs,
sentinelsToAdd,
sweepTimestamp,
sweepLastCommitted,
sweepStrategy);
cellTsMappingsToSweep.putAll(entry.getKey(), timestampsToSweep);
}
return cellTsMappingsToSweep;
}