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Subject git commit: ACCUMULO-2847 Add a section on ReplicaSystems
Date Thu, 29 May 2014 17:31:43 GMT
Repository: accumulo
Updated Branches:
  refs/heads/ACCUMULO-378 47e2983ec -> 73d34ec71

ACCUMULO-2847 Add a section on ReplicaSystems


Branch: refs/heads/ACCUMULO-378
Commit: 73d34ec7112be43c568cff1ea8b8458079c432e3
Parents: 47e2983
Author: Josh Elser <>
Authored: Thu May 29 13:31:20 2014 -0400
Committer: Josh Elser <>
Committed: Thu May 29 13:31:20 2014 -0400

 docs/src/main/asciidoc/chapters/replication.txt | 22 ++++++++++++++++++++
 1 file changed, 22 insertions(+)
diff --git a/docs/src/main/asciidoc/chapters/replication.txt b/docs/src/main/asciidoc/chapters/replication.txt
index 20843a9..9f367df 100644
--- a/docs/src/main/asciidoc/chapters/replication.txt
+++ b/docs/src/main/asciidoc/chapters/replication.txt
@@ -160,3 +160,25 @@ it's possible that multiple versions of the same Key with different values
are i
 In this case, parallel replication to a peer and target is possible without any downsides.
In the case
 where this implementation is used were column updates are frequent, it is possible that there
will be
 an inconsistency between the primary and the peer.
+=== ReplicaSystems
++ReplicaSystem+ is the interface which allows abstraction of replication of data
+to peers of various types. Presently, only an +AccumuloReplicaSystem+ is provided
+which will replicate data to another Accumulo instance. A +ReplicaSystem+ implementation
+is run inside of the TabletServer process, and can be configured as mentioned in the 
++Instance Configuration+ section of this document. Theoretically, an implementation
+of this interface could send data to other filesystems, databases, etc.
+==== AccumuloReplicaSystem
+The +AccumuloReplicaSystem+ uses Thrift to communicate with a peer Accumulo instance
+and replicate the necessary data. The TabletServer running on the primary will communicate
+with the Master on the peer to request the address of a TabletServer on the peer which
+this TabletServer will use to replicate the data.
+The TabletServer on the primary will then replicate data in batches of a configurable
+size (+replication.max.unit.size+). The TabletServer on the peer will report how many
+records were applied back to the primary, which will be used to record how many records
+were successfully replicated. The TabletServer on the primary will continue to replicate
+data in these batches until no more data can be read from the file.

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