Github user kxepal commented on a diff in the pull request:
https://github.com/apache/couchdb-mem3/pull/8#discussion_r26462778
--- Diff: README.md ---
@@ -1,33 +1,42 @@
## mem3
-Mem3 is the node membership application for clustered [CouchDB][1]. It is
used in [BigCouch][2] and tracks two very important things for the cluster:
+Mem3 is the node membership application for clustered [CouchDB][1]. It is
used
+in CouchDB since version 2.0 and tracks two very important things for the
+cluster:
1. member nodes
2. node/shards mappings for each database
-Both the nodes and shards are tracked in node-local couch databases.
Shards are heavily used, so an ETS cache is also maintained for low-latency
lookups. The nodes and shards are synchronized via continuous CouchDB
replication, which serves as 'gossip' in Dynamo parlance. The shards ETS cache
is kept in sync based on membership and database event listeners.
-
-A very important point to make here is that BigCouch does not necessarily
divide up each database into equal shards across the nodes of a cluster. For
instance, in a 20-node cluster, you may have the need to create a small
database with very few documents. For efficiency reasons, you may create your
database with Q=4 and keep the default of N=3. This means you only have 12
shards total, so 8 nodes will hold none of the data for this database. Given
this feature, we even shard use out across the cluster by altering the 'start'
node for the database's shards.
-
-Splitting and merging shards is an immature feature of the system, and
will require attention in the near-term. We believe we can implement both
functions and perform them while the database remains online.
+Both the nodes and shards are tracked in node-local couch databases.
Shards
+are heavily used, so an ETS cache is also maintained for low-latency
lookups.
+The nodes and shards are synchronized via continuous CouchDB replication,
+which serves as 'gossip' in Dynamo parlance. The shards ETS cache is kept
in
+sync based on membership and database event listeners.
+
+A very important point to make here is that CouchDB >= 2.0 does not
--- End diff --
>= (;
However, here no need "since" imho an even version mention. Just CouchDB.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
