So HDFS is for durability while replication is for availability? I'm
assuming that the client is unaware of the replicated instance and queries
the DB with no knowledge of which instance/table will return the result.

Best regards,
Yamini Joshi

On Thu, Oct 13, 2016 at 11:46 AM, Josh Elser <> wrote:

> I'm not familiar with MongoDB. Perhaps someone else can confirm this for
> you.
> Yamini Joshi wrote:
>> So, can I say that if I have a table split across nodes (i.e. num
>> tablets > 1) and HDFS replication in my system, it is sort of equivalent
>> to a sharded and replicated mongo architecture?
>> Best regards,
>> Yamini Joshi
>> On Thu, Oct 13, 2016 at 11:06 AM, Josh Elser <
>> <>> wrote:
>>     The Accumulo (Data Center) Replication feature is for having
>>     multiple active Accumulo clusters all containing the same data.
>>     HDFS provides replication as a means for durability of the data it
>>     is storing. The files that Accumulo creates on one HDFS instance are
>>     replicated by HDFS. This does not help if your entire cluster become
>>     unavailable. That is what the data center replication Accumulo
>>     feature solves.
>>     While both can be called "replication", they serve very different
>>     purposes.
>>     Yamini Joshi wrote:
>>         Hello
>>         I was going through some Accumulo docs and found out about
>>         replication.
>>         To enable replication,one needs to make some config settings as
>>         described in
>> /asciidoc/chapters/replication.txt
>>         <
>> n/asciidoc/chapters/replication.txt>.
>>         I cannot seem to grasp the difference between this replication
>>         conf and
>>         the replication on HDFS level. What exactly is the use case for
>>         replication? Are the replicated instances visible to the clients?
>>         Best regards,
>>         Yamini Joshi

Reply via email to