[jira] [Updated] (HBASE-5482) In 0.90, balancer algo leading to same region balanced twice and picking same region with Src and Destination as same RS.

2012-03-01 Thread ramkrishna.s.vasudevan (Updated) (JIRA) 

 [ 
https://issues.apache.org/jira/browse/HBASE-5482?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

ramkrishna.s.vasudevan updated HBASE-5482:
--

Attachment: HBASE-5482_2.patch

Patch addressing Ted's comments.  
@Ted
If the patch is fine, we can commit it for 0.90.7?

 In 0.90, balancer algo leading to same region balanced twice and picking same 
 region with Src and Destination as same RS.
 -

 Key: HBASE-5482
 URL: https://issues.apache.org/jira/browse/HBASE-5482
 Project: HBase
  Issue Type: Bug
  Components: master
Affects Versions: 0.90.5
Reporter: ramkrishna.s.vasudevan
Assignee: ramkrishna.s.vasudevan
 Fix For: 0.90.7

 Attachments: 5482-v2.txt, HBASE-5482_1.patch, HBASE-5482_2.patch


 There are possibility of 2 problems
 - When we populate regionsToMove while iterating the serverinfo in 
 descending manner there is a chance that the same region can be added twice.
 Because in the first loop we do a randomization of the regions.
 Where as when we get we have neededRegions!= 0 we just get the region in the 
 index and add it again . This may lead to have same region in the 
 regionsToMove list.
 - Another problem is 
 when the problem in the first point happens then there is a chance that
 the regionToMove can have the same src and destination and the same region 
 can be picked every 5 mins.
 {code}
 for(Map.EntryHServerInfo, ListHRegionInfo server :
 serversByLoad.descendingMap().entrySet()) {
 BalanceInfo balanceInfo = serverBalanceInfo.get(server.getKey());
 int idx =
   balanceInfo == null ? 0 : balanceInfo.getNextRegionForUnload();
 if (idx = server.getValue().size()) break;
 HRegionInfo region = server.getValue().get(idx);
 if (region.isMetaRegion()) continue; // Don't move meta regions.
 regionsToMove.add(new RegionPlan(region, server.getKey(), null));
 if(--neededRegions == 0) {
   // No more regions needed, done shedding
   break;
 }
   }
 {code}
 If i have meta and root in the top two loaded region server(totally 3 RS), we 
 just skip the regions in those region server and populate the region from the 
 least loaded RS.
 Then in the next loop we iterate from the least loaded server and populate 
 the destination as also the same server.
 This is leading to a condition where every 5 min balancing happens and also 
 the server is same for src and dest.

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[jira] [Updated] (HBASE-5482) In 0.90, balancer algo leading to same region balanced twice and picking same region with Src and Destination as same RS.

2012-02-29 Thread Zhihong Yu (Updated) (JIRA) 

 [ 
https://issues.apache.org/jira/browse/HBASE-5482?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Zhihong Yu updated HBASE-5482:
--

Attachment: 5482-v2.txt

Patch v2 corrected grammar in comments

 In 0.90, balancer algo leading to same region balanced twice and picking same 
 region with Src and Destination as same RS.
 -

 Key: HBASE-5482
 URL: https://issues.apache.org/jira/browse/HBASE-5482
 Project: HBase
  Issue Type: Bug
  Components: master
Affects Versions: 0.90.5
Reporter: ramkrishna.s.vasudevan
Assignee: ramkrishna.s.vasudevan
 Fix For: 0.90.7

 Attachments: 5482-v2.txt, HBASE-5482_1.patch


 There are possibility of 2 problems
 - When we populate regionsToMove while iterating the serverinfo in 
 descending manner there is a chance that the same region can be added twice.
 Because in the first loop we do a randomization of the regions.
 Where as when we get we have neededRegions!= 0 we just get the region in the 
 index and add it again . This may lead to have same region in the 
 regionsToMove list.
 - Another problem is 
 when the problem in the first point happens then there is a chance that
 the regionToMove can have the same src and destination and the same region 
 can be picked every 5 mins.
 {code}
 for(Map.EntryHServerInfo, ListHRegionInfo server :
 serversByLoad.descendingMap().entrySet()) {
 BalanceInfo balanceInfo = serverBalanceInfo.get(server.getKey());
 int idx =
   balanceInfo == null ? 0 : balanceInfo.getNextRegionForUnload();
 if (idx = server.getValue().size()) break;
 HRegionInfo region = server.getValue().get(idx);
 if (region.isMetaRegion()) continue; // Don't move meta regions.
 regionsToMove.add(new RegionPlan(region, server.getKey(), null));
 if(--neededRegions == 0) {
   // No more regions needed, done shedding
   break;
 }
   }
 {code}
 If i have meta and root in the top two loaded region server(totally 3 RS), we 
 just skip the regions in those region server and populate the region from the 
 least loaded RS.
 Then in the next loop we iterate from the least loaded server and populate 
 the destination as also the same server.
 This is leading to a condition where every 5 min balancing happens and also 
 the server is same for src and dest.

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[jira] [Updated] (HBASE-5482) In 0.90, balancer algo leading to same region balanced twice and picking same region with Src and Destination as same RS.

2012-02-28 Thread ramkrishna.s.vasudevan (Updated) (JIRA) 

 [ 
https://issues.apache.org/jira/browse/HBASE-5482?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

ramkrishna.s.vasudevan updated HBASE-5482:
--

Attachment: HBASE-5482_1.patch

Patch for 0.90.

 In 0.90, balancer algo leading to same region balanced twice and picking same 
 region with Src and Destination as same RS.
 -

 Key: HBASE-5482
 URL: https://issues.apache.org/jira/browse/HBASE-5482
 Project: HBase
  Issue Type: Bug
  Components: master
Affects Versions: 0.90.5
Reporter: ramkrishna.s.vasudevan
Assignee: ramkrishna.s.vasudevan
 Fix For: 0.90.7

 Attachments: HBASE-5482_1.patch


 There are possibility of 2 problems
 - When we populate regionsToMove while iterating the serverinfo in 
 descending manner there is a chance that the same region can be added twice.
 Because in the first loop we do a randomization of the regions.
 Where as when we get we have neededRegions!= 0 we just get the region in the 
 index and add it again . This may lead to have same region in the 
 regionsToMove list.
 - Another problem is 
 when the problem in the first point happens then there is a chance that
 the regionToMove can have the same src and destination and the same region 
 can be picked every 5 mins.
 {code}
 for(Map.EntryHServerInfo, ListHRegionInfo server :
 serversByLoad.descendingMap().entrySet()) {
 BalanceInfo balanceInfo = serverBalanceInfo.get(server.getKey());
 int idx =
   balanceInfo == null ? 0 : balanceInfo.getNextRegionForUnload();
 if (idx = server.getValue().size()) break;
 HRegionInfo region = server.getValue().get(idx);
 if (region.isMetaRegion()) continue; // Don't move meta regions.
 regionsToMove.add(new RegionPlan(region, server.getKey(), null));
 if(--neededRegions == 0) {
   // No more regions needed, done shedding
   break;
 }
   }
 {code}
 If i have meta and root in the top two loaded region server(totally 3 RS), we 
 just skip the regions in those region server and populate the region from the 
 least loaded RS.
 Then in the next loop we iterate from the least loaded server and populate 
 the destination as also the same server.
 This is leading to a condition where every 5 min balancing happens and also 
 the server is same for src and dest.

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[jira] [Updated] (HBASE-5482) In 0.90, balancer algo leading to same region balanced twice and picking same region with Src and Destination as same RS.

2012-02-27 Thread ramkrishna.s.vasudevan (Updated) (JIRA) 

 [ 
https://issues.apache.org/jira/browse/HBASE-5482?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

ramkrishna.s.vasudevan updated HBASE-5482:
--

Summary: In 0.90, balancer algo leading to same region balanced twice and 
picking same region with Src and Destination as same RS.  (was: Balancer in 
0.90 algo leading to same region balanced twice and picking same region with 
Src and Destination as same RS.)

 In 0.90, balancer algo leading to same region balanced twice and picking same 
 region with Src and Destination as same RS.
 -

 Key: HBASE-5482
 URL: https://issues.apache.org/jira/browse/HBASE-5482
 Project: HBase
  Issue Type: Bug
  Components: master
Affects Versions: 0.90.5
Reporter: ramkrishna.s.vasudevan
Assignee: ramkrishna.s.vasudevan
 Fix For: 0.90.7


 There are possibility of 2 problems
 - When we populate regionsToMove while iterating the serverinfo in 
 descending manner there is a chance that the same region can be added twice.
 Because in the first loop we do a randomization of the regions.
 Where as when we get we have neededRegions!= 0 we just get the region in the 
 index and add it again . This may lead to have same region in the 
 regionsToMove list.
 - Another problem is 
 when the problem in the first point happens then there is a chance that
 the regionToMove can have the same src and destination and the same region 
 can be picked every 5 mins.
 {code}
 for(Map.EntryHServerInfo, ListHRegionInfo server :
 serversByLoad.descendingMap().entrySet()) {
 BalanceInfo balanceInfo = serverBalanceInfo.get(server.getKey());
 int idx =
   balanceInfo == null ? 0 : balanceInfo.getNextRegionForUnload();
 if (idx = server.getValue().size()) break;
 HRegionInfo region = server.getValue().get(idx);
 if (region.isMetaRegion()) continue; // Don't move meta regions.
 regionsToMove.add(new RegionPlan(region, server.getKey(), null));
 if(--neededRegions == 0) {
   // No more regions needed, done shedding
   break;
 }
   }
 {code}
 If i have meta and root in the top two loaded region server(totally 3 RS), we 
 just skip the regions in those region server and populate the region from the 
 least loaded RS.
 Then in the next loop we iterate from the least loaded server and populate 
 the destination as also the same server.
 This is leading to a condition where every 5 min balancing happens and also 
 the server is same for src and dest.

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