From c3ab1fc817e30b94d0154e48b13bc651ee177643 Mon Sep 17 00:00:00 2001
From: Angel Borroy <angel.borroy@alfresco.com>
Date: Wed, 8 Jan 2020 14:45:49 +0100
Subject: [PATCH] Use the feature only when nextTxCommitTime Web Script is
 available in the repository.

---
 .../solr/tracker/MetadataTracker.java         | 24 +++++++++++++++++--
 .../alfresco/solr/client/SOLRAPIClient.java   |  1 -
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/MetadataTracker.java b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/MetadataTracker.java
index 7c0df7841..a3a00fd2e 100644
--- a/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/MetadataTracker.java
+++ b/search-services/alfresco-search/src/main/java/org/alfresco/solr/tracker/MetadataTracker.java
@@ -63,6 +63,16 @@ public class MetadataTracker extends CoreStatePublisher implements Tracker
     private ConcurrentLinkedQueue<Long> nodesToIndex = new ConcurrentLinkedQueue<>();
     private ConcurrentLinkedQueue<Long> nodesToPurge = new ConcurrentLinkedQueue<>();
     private ConcurrentLinkedQueue<String> queriesToReindex = new ConcurrentLinkedQueue<>();
+    
+    /**
+     * Check if nextTxCommitTimeService is available in the repository.
+     * This service is used to find the next available transaction commit time from a given time,
+     * so periods of time where no document updating is happening can be skipped while getting 
+     * pending transactions list.
+     * 
+     * {@link org.alfresco.solr.client.SOLRAPIClient#GET_NEXT_TX_COMMIT_TIME}
+     */
+    private boolean nextTxCommitTimeServiceAvailable = false;
 
     public MetadataTracker(final boolean isMaster, Properties p, SOLRAPIClient client, String coreName,
                 InformationServer informationServer)
@@ -71,6 +81,16 @@ public class MetadataTracker extends CoreStatePublisher implements Tracker
         transactionDocsBatchSize = Integer.parseInt(p.getProperty("alfresco.transactionDocsBatchSize", "100"));
         nodeBatchSize = Integer.parseInt(p.getProperty("alfresco.nodeBatchSize", "10"));
         threadHandler = new ThreadHandler(p, coreName, "MetadataTracker");
+        
+        try
+        {
+            client.getNextTxCommitTime(coreName, 0l);
+            nextTxCommitTimeServiceAvailable = true;
+        }
+        catch (Exception e)
+        {
+            log.warn("nextTxCommitTimeService is not available. Upgrade your ACS Repository version in order to use this feature", e);
+        }
     }
 
     MetadataTracker()
@@ -548,12 +568,12 @@ public class MetadataTracker extends CoreStatePublisher implements Tracker
             startTime += actualTimeStep;
             
             // If no transactions are found, advance the time window to the next available transaction commit time
-            if (transactions.getTransactions().size() == 0)
+            if (nextTxCommitTimeServiceAvailable && transactions.getTransactions().size() == 0)
             {
                 Long nextTxCommitTime = client.getNextTxCommitTime(coreName, startTime);
                 if (nextTxCommitTime != -1)
                 {
-                    log.info("Advancing transactions from startTime = " + startTime + " to " + nextTxCommitTime);
+                    log.info("Advancing transactions from {} to {}", startTime, nextTxCommitTime);
                     transactions = client.getTransactions(nextTxCommitTime, null, nextTxCommitTime + actualTimeStep, null, maxResults, shardstate);
                 }
             }
diff --git a/search-services/alfresco-solrclient-lib/src/main/java/org/alfresco/solr/client/SOLRAPIClient.java b/search-services/alfresco-solrclient-lib/src/main/java/org/alfresco/solr/client/SOLRAPIClient.java
index 2be8197e1..eb2142ff1 100644
--- a/search-services/alfresco-solrclient-lib/src/main/java/org/alfresco/solr/client/SOLRAPIClient.java
+++ b/search-services/alfresco-solrclient-lib/src/main/java/org/alfresco/solr/client/SOLRAPIClient.java
@@ -1239,7 +1239,6 @@ public class SOLRAPIClient
      * @return Time of the next transaction
      * @throws IOException 
      * @throws AuthenticationException 
-     * @throws Exception
      */
     public Long getNextTxCommitTime(String coreName, Long fromCommitTime) throws AuthenticationException, IOException
     {