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https://issues.apache.org/jira/browse/CASSANDRA-17759?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17567937#comment-17567937
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Stefan Miklosovic commented on CASSANDRA-17759:
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Ok this is interesting.
I have a 3-nodes cluster out of which 2 nodes are gossipping only members so we
have 1 data node only.
When I try to execute this on data node, I get:
{code:java}
cqlsh> CREATE KEYSPACE abc WITH replication = {'class':
'NetworkTopologyStrategy', 'dc1': 3};
Warnings :
Your replication factor 3 for keyspace abc is higher than the number of nodes 1
for datacenter dc1
{code}
So, this is ok.
However, when I create that keyspace on one of gossipping-only members, I get
this:
{code:java}
cqlsh> CREATE KEYSPACE abc WITH replication = {'class':
'NetworkTopologyStrategy', 'dc1': 3};
Warnings :
Your replication factor 3 for keyspace abc is higher than the number of nodes 2
for datacenter dc1
{code}
Do you see that "2"? It seems like it counts itself as replica but that logic
executed on the data node properly sees that that there is 1 replica only.
I ll dig deeper whats up. We might filter out that from the map when it is not
a member (Gossipper#isGossipOnlyMember)
> Creation of a keyspace with RF equal to all nodes including gossipping-only
> members should fail
> -----------------------------------------------------------------------------------------------
>
> Key: CASSANDRA-17759
> URL: https://issues.apache.org/jira/browse/CASSANDRA-17759
> Project: Cassandra
> Issue Type: New Feature
> Reporter: Stefan Miklosovic
> Priority: Normal
>
> Imagine there is a 5-node cluster where two nodes are gossipping-only members
> (-Dcassandra.join_ring=false) - or in other words, 3 data nodes and 2
> "coordinator" nodes.
> Coordinator nodes are capable to speak CQL as well so requests can be
> executed against them. If we create a keyspace against such node, like
> "create keyspace ks1 with replication = {class = "NTS", "dc1": 5}, this query
> succeeds but if we set CONSISTENCY to ALL in cqlsh and we try to insert some
> data into a table of such keyspace, it will fail - because it does not have
> enough replicas. It has only 3.
> If this query is executed on data node (a proper member of a ring), this
> should fail too. I think there is a mechanism how to do this, like by
> Guardrails but there is no check which would include gossipping-only members
> into consideration.
> Ideally, we might introduce a check which would check that the replication
> factor is at most as big as the number of members - irrelevant of their
> current status, they just have to be members of the ring.
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