[asterixdb] branch master updated: [ASTERIXDB-2522][TX] Skip WAIT record during lock conflicts

[lu...@apache.org]

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luochen pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/asterixdb.git


The following commit(s) were added to refs/heads/master by this push:
     new e060d5c  [ASTERIXDB-2522][TX] Skip WAIT record during lock conflicts
e060d5c is described below

commit e060d5cfe8138339475a4ac69e38154e81eaa553
Author: luochen <cl...@uci.edu>
AuthorDate: Wed Feb 27 20:44:59 2019 -0800

    [ASTERIXDB-2522][TX] Skip WAIT record during lock conflicts
    
    - user model changes: no
    - storage format changes: no
    - interface changes: no
    
    Details:
    - A small optimization to our deadlock-free locking potocol by skipping
    the WAIT record. Once the partial frame has been flushed and previous
    records are committed, the locks held by the write thread will
    eventually be released by the log flusher thread. There is no need to
    force the writer thread to wait for the log flusher thread.
    
    Change-Id: I6ef3979d6393d45a6b7b2eb5f09f147299b5cd9f
    Reviewed-on: https://asterix-gerrit.ics.uci.edu/3232
    Sonar-Qube: Jenkins <je...@fulliautomatix.ics.uci.edu>
    Tested-by: Jenkins <je...@fulliautomatix.ics.uci.edu>
    Contrib: Jenkins <je...@fulliautomatix.ics.uci.edu>
    Integration-Tests: Jenkins <je...@fulliautomatix.ics.uci.edu>
    Reviewed-by: Murtadha Hubail <mh...@apache.org>
---
 .../PrimaryIndexModificationOperationCallback.java    | 19 +++----------------
 1 file changed, 3 insertions(+), 16 deletions(-)

diff --git a/asterixdb/asterix-transactions/src/main/java/org/apache/asterix/transaction/management/opcallbacks/PrimaryIndexModificationOperationCallback.java b/asterixdb/asterix-transactions/src/main/java/org/apache/asterix/transaction/management/opcallbacks/PrimaryIndexModificationOperationCallback.java
index 3e41264..690ef1f 100644
--- a/asterixdb/asterix-transactions/src/main/java/org/apache/asterix/transaction/management/opcallbacks/PrimaryIndexModificationOperationCallback.java
+++ b/asterixdb/asterix-transactions/src/main/java/org/apache/asterix/transaction/management/opcallbacks/PrimaryIndexModificationOperationCallback.java
@@ -62,11 +62,9 @@ public class PrimaryIndexModificationOperationCallback extends AbstractIndexModi
                  * 3. if returnValue == false
                  * 3-1. flush all entries (which already acquired locks) to the next operator
                  * : this will make all those entries reach commit operator so that corresponding commit logs will be created.
-                 * 3-2. create a WAIT log and wait until logFlusher thread will flush the WAIT log and gives notification
-                 * : this notification guarantees that all locks acquired by this transactor (or all locks acquired for the entries)
-                 * were released.
-                 * 3-3. acquire lock using lock() instead of tryLock() for the failed entry
-                 * : we know for sure this lock call will not cause deadlock since the transactor doesn't hold any other locks.
+                 * 3-2. acquire lock using lock() instead of tryLock() for the failed entry
+                 * : we know for sure this lock call will not cause deadlock since the locks held by the transactor
+                 * will be eventually released by the log flusher.
                  * 4. create an update log and insert the entry
                  * From the above logic, step 2 and 3 are implemented in this before() method.
                  **********************/
@@ -77,9 +75,6 @@ public class PrimaryIndexModificationOperationCallback extends AbstractIndexModi
                     //flush entries which have been inserted already to release locks hold by them
                     operatorNodePushable.flushPartialFrame();
 
-                    //create WAIT log and wait until the WAIT log is flushed and notified by LogFlusher thread
-                    logWait();
-
                     //acquire lock
                     lockManager.lock(datasetId, pkHash, LockMode.X, txnCtx);
                 }
@@ -102,12 +97,4 @@ public class PrimaryIndexModificationOperationCallback extends AbstractIndexModi
             throw HyracksDataException.create(e);
         }
     }
-
-    private void logWait() throws ACIDException {
-        indexRecord.setLogType(LogType.WAIT);
-        indexRecord.computeAndSetLogSize();
-        txnSubsystem.getLogManager().log(indexRecord);
-        // set the log type back to UPDATE for normal updates
-        indexRecord.setLogType(LogType.UPDATE);
-    }
 }