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@@ -87,7 +87,7 @@ In order to deploy an HA cluster, you should prepare the following:
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* **NameNode machines** - the machines on which you run the Active and Standby NameNodes should have equivalent hardware to each other, and equivalent hardware to what would be used in a non-HA cluster.
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-* **Shared storage** - you will need to have a shared directory which the NameNode machines have read/write access to. Typically this is a remote filer which supports NFS and is mounted on each of the NameNode machines. Currently only a single shared edits directory is supported. Thus, the availability of the system is limited by the availability of this shared edits directory, and therefore in order to remove all single points of failure there needs to be redundancy for the shared edits directory. Specifically, multiple network paths to the storage, and redundancy in the storage itself (disk, network, and power). Beacuse of this, it is recommended that the shared storage server be a high-quality dedicated NAS appliance rather than a simple Linux server.
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+* **Shared storage** - you will need to have a shared directory which the NameNode machines have read/write access to. Typically this is a remote filer which supports NFS and is mounted on each of the NameNode machines. Currently only a single shared edits directory is supported. Thus, the availability of the system is limited by the availability of this shared edits directory, and therefore in order to remove all single points of failure there needs to be redundancy for the shared edits directory. Specifically, multiple network paths to the storage, and redundancy in the storage itself (disk, network, and power). Because of this, it is recommended that the shared storage server be a high-quality dedicated NAS appliance rather than a simple Linux server.
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Note that, in an HA cluster, the Standby NameNodes also perform checkpoints of the namespace state, and thus it is not necessary to run a Secondary NameNode, CheckpointNode, or BackupNode in an HA cluster. In fact, to do so would be an error. This also allows one who is reconfiguring a non-HA-enabled HDFS cluster to be HA-enabled to reuse the hardware which they had previously dedicated to the Secondary NameNode.
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@@ -137,7 +137,7 @@ The order in which you set these configurations is unimportant, but the values y
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* **dfs.namenode.rpc-address.[nameservice ID].[name node ID]** - the fully-qualified RPC address for each NameNode to listen on
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For both of the previously-configured NameNode IDs, set the full address and
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- IPC port of the NameNode processs. Note that this results in two separate
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+ IPC port of the NameNode process. Note that this results in two separate
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configuration options. For example:
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<property>
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