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The following page has been changed by stack: http://wiki.apache.org/hadoop/Hbase/Troubleshooting The comment on the change is: Added TOC ------------------------------------------------------------------------------ + == Contents == + 1. [#1 Problem: Master initializes, but Region Servers do not] + 1. [#2 Problem: Created Root Directory for HBase through Hadoop DFS] + 1. [#3 Problem: Replay of hlog required, forcing regionserver restart] + 2. [#4 Problem: Master initializes, but Region Servers do not] + 1. [#5 Problem: On migration, no files in root directory] + + [[Anchor(1)]] == Problem: Master initializes, but Region Servers do not == * Master's log contains repeated instances of the following block: ~-INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /127.0.0.1:60020. Already tried 1 time(s).[[BR]] @@ -30, +38 @@ 127.0.0.1 localhost.localdomain localhost ::1 localhost6.localdomain6 localhost6 }}} + [[Anchor(2)]] == Problem: Created Root Directory for HBase through Hadoop DFS == * On Startup, Master says that you need to run the hbase migrations script. Upon running that, the hbase migrations script says no files in root directory. === Causes === @@ -37, +46 @@ === Resolution === * Make sure the HBase root directory does not currently exist or has been initialized by a previous run of HBase. Sure fire solution is to just use Hadoop dfs to delete the HBase root and let HBase create and initialize the directory itself. + [[Anchor(3)]] == Problem: Replay of hlog required, forcing regionserver restart == * Under a heavy write load, some regions servers will go down with the following exception: {{{ @@ -57, +67 @@ === Resolution === * Either reduce the load or add more memory/machines. - + [[Anchor(4)]] == Problem: Master initializes, but Region Servers do not == * Master's log contains repeated instances of the following block: ~-INFO org.apache.hadoop.ipc.Client: Retrying connect to server: /127.0.0.1:60020. Already tried 1 time(s).[[BR]] @@ -88, +98 @@ 127.0.0.1 localhost.localdomain localhost ::1 localhost6.localdomain6 localhost6 }}} - == Problem: Created Root Directory for HBase through Hadoop DFS == + + [[Anchor(5)]] + == Problem: On migration, no files in root directory == * On Startup, Master says that you need to run the hbase migrations script. Upon running that, the hbase migrations script says no files in root directory. === Causes === * HBase expects the root directory to either not exist, or to have already been initialized by hbase running a previous time. If you create a new directory for HBase using Hadoop DFS, this error will occur.
