[
https://issues.apache.org/jira/browse/TEPHRA-35?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15645751#comment-15645751
]
ASF GitHub Bot commented on TEPHRA-35:
--------------------------------------
Github user poornachandra commented on a diff in the pull request:
https://github.com/apache/incubator-tephra/pull/19#discussion_r86889731
--- Diff: tephra-core/src/main/java/org/apache/tephra/util/TxUtils.java ---
@@ -149,4 +149,15 @@ private static long getMaxTTL(Map<byte[], Long>
ttlByFamily) {
public static boolean isPreExistingVersion(long version) {
return version < MAX_NON_TX_TIMESTAMP;
}
+
+ /**
+ * Returns the maximum transaction that can be removed from the invalid
list for the state represented by the given
+ * transaction.
+ */
+ public static long getPruneUpperBound(Transaction tx) {
+ long maxInvalidTx =
+ tx.getInvalids().length > 0 ?
tx.getInvalids()[tx.getInvalids().length - 1] : Transaction.NO_TX_IN_PROGRESS;
+ long firstInProgress = tx.getFirstInProgress();
+ return Math.min(maxInvalidTx, firstInProgress - 1);
--- End diff --
Good catch, updated the code to use the current read pointer in such a case
> Prune invalid transaction set once all data for a given invalid transaction
> has been dropped
> --------------------------------------------------------------------------------------------
>
> Key: TEPHRA-35
> URL: https://issues.apache.org/jira/browse/TEPHRA-35
> Project: Tephra
> Issue Type: New Feature
> Reporter: Gary Helmling
> Assignee: Poorna Chandra
> Priority: Blocker
> Attachments: ApacheTephraAutomaticInvalidListPruning-v2.pdf
>
>
> In addition to dropping the data from invalid transactions we need to be able
> to prune the invalid set of any transactions where data cleanup has been
> completely performed. Without this, the invalid set will grow indefinitely
> and become a greater and greater cost to in-progress transactions over time.
> To do this correctly, the TransactionDataJanitor coprocessor will need to
> maintain some bookkeeping for the transaction data that it removes, so that
> the transaction manager can reason about when all of a given transaction's
> data has been removed. Only at this point can the transaction manager safely
> drop the transaction ID from the invalid set.
> One approach would be for the TransactionDataJanitor to update a table
> marking when a major compaction was performed on a region and what
> transaction IDs were filtered out. Once all regions in a table containing the
> transaction data have been compacted, we can remove the filtered out
> transaction IDs from the invalid set. However, this will need to cope with
> changing region names due to splits, etc.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
