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HBase >> mail # user >> Is "synchronized" required?


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Bing Li 2013-02-04, 20:20
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Re: Is "synchronized" required?
What exceptions do you actually receive - can you send them here?
Knowing that is key to addressing your issue.

On Tue, Feb 5, 2013 at 1:50 AM, Bing Li <[EMAIL PROTECTED]> wrote:
> Dear all,
>
> When writing data into HBase, sometimes I got exceptions. I guess they
> might be caused by concurrent writings. But I am not sure.
>
> My question is whether it is necessary to put "synchronized" before
> the writing methods? The following lines are the sample code.
>
> I think the directive, synchronized, must lower the performance of
> writing. Sometimes concurrent writing is needed in my system.
>
> Thanks so much!
>
> Best wishes,
> Bing
>
> public synchronized void AddDomainNodeRanks(String domainKey, int
> timingScale, Map<String, Double> nodeRankMap)
> {
>       List<Put> puts = new ArrayList<Put>();
>       Put domainKeyPut;
>       Put timingScalePut;
>       Put nodeKeyPut;
>       Put rankPut;
>
>       byte[] domainNodeRankRowKey;
>
>       for (Map.Entry<String, Double> nodeRankEntry : nodeRankMap.entrySet())
>       {
>           domainNodeRankRowKey > Bytes.toBytes(RankStructure.DOMAIN_NODE_RANK_ROW +
> Tools.GetAHash(domainKey + timingScale + nodeRankEntry.getKey()));
>
>          domainKeyPut = new Put(domainNodeRankRowKey);
>          domainKeyPut.add(RankStructure.DOMAIN_NODE_RANK_FAMILY,
> RankStructure.DOMAIN_NODE_RANK_DOMAIN_KEY_COLUMN,
> Bytes.toBytes(domainKey));
>          puts.add(domainKeyPut);
>
>          timingScalePut = new Put(domainNodeRankRowKey);
>          timingScalePut.add(RankStructure.DOMAIN_NODE_RANK_FAMILY,
> RankStructure.DOMAIN_NODE_RANK_TIMING_SCALE_COLUMN,
> Bytes.toBytes(timingScale));
>         puts.add(timingScalePut);
>
>         nodeKeyPut = new Put(domainNodeRankRowKey);
>         nodeKeyPut.add(RankStructure.DOMAIN_NODE_RANK_FAMILY,
> RankStructure.DOMAIN_NODE_RANK_NODE_KEY_COLUMN,
> Bytes.toBytes(nodeRankEntry.getKey()));
>         puts.add(nodeKeyPut);
>
>         rankPut = new Put(domainNodeRankRowKey);
>         rankPut.add(RankStructure.DOMAIN_NODE_RANK_FAMILY,
> RankStructure.DOMAIN_NODE_RANK_RANKS_COLUMN,
> Bytes.toBytes(nodeRankEntry.getValue()));
>         puts.add(rankPut);
>      }
>
>      try
>      {
>          this.rankTable.put(puts);
>      }
>      catch (IOException e)
>      {
>          e.printStackTrace();
>      }
> }

--
Harsh J
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Ted Yu 2013-02-04, 20:25
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Bing Li 2013-02-04, 20:32
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Haijia Zhou 2013-02-04, 20:42
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Adrien Mogenet 2013-02-04, 21:13
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Nicolas Liochon 2013-02-04, 21:31
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Bing Li 2013-02-04, 22:40
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Nicolas Liochon 2013-02-04, 22:49
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Bing Li 2013-02-05, 16:54
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lars hofhansl 2013-02-06, 05:05
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Bing Li 2013-02-07, 08:10
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lars hofhansl 2013-02-07, 17:24
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Bing Li 2013-02-06, 06:36
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Adrien Mogenet 2013-02-06, 07:45
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lars hofhansl 2013-02-06, 07:44
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Bing Li 2013-02-06, 10:31
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lars hofhansl 2013-02-06, 18:54