Well I tried to drop the keyspace, but it's still there. No errors in logs and
Cassandra-cli showed the schema agreement after the command. I took a snapshot
of the system keyspace first. Nothing is crashing in the clients yet either,
still able to read/write to that keyspace.
[default@EBonding] drop keyspace EBonding;
2eb11095-b8a8-31cd-80c3-c748d32a4208
Waiting for schema agreement...
... schemas agree across the cluster
[default@unknown] use EBonding;
Authenticated to keyspace: EBonding
[default@EBonding] describe;
Keyspace: EBonding:
Replication Strategy: org.apache.cassandra.locator.SimpleStrategy
Durable Writes: true
Options: [replication_factor:2]
From: aaron morton [mailto:aa...@thelastpickle.com]
Sent: Wednesday, August 29, 2012 2:36 AM
To: user@cassandra.apache.org
Subject: Re: Expanding cluster to include a new DR datacenter
It would be handy to work out what the corruption is. Could you snapshot the
system keyspace and store it somewhere, just incase we can look at it later ?
Is there a way I can confirm this
Errors in the client and/or the server log is the the traditional way.
go about cleaning up/restoring the proper schema?
If you need to get it back, and can handle the down time, the simple thing is
drop the KS and re-create it. Remember to take a snapshot first. Drop keyspace
takes one but it's the sort of thing I would do myself.
Or you can try _try_ nodetool resetlocalschema. Without knowing what the error
is it's hard to say if it would work.
Cheers
-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com
On 29/08/2012, at 9:10 AM, Bryce Godfrey
<bryce.godf...@azaleos.com<mailto:bryce.godf...@azaleos.com>> wrote:
I believe what may be really going on is that my schema is in a bad or corrupt
state. I also have one keyspace that I just cannot drop an existing column
family from even though it shows no errors.
So right now I was able to get 4 of my 6 keyspaces over to Network Topology
strategy.
I think I got into this bad state after pointing Opscenter at this cluster for
the first time, as it started throwing errors after that and crashed a couple
of my nodes until I stopped it and its agents.
Is there a way I can confirm this or go about cleaning up/restoring the proper
schema?
From: Bryce Godfrey [mailto:bryce.godf...@azaleos.com<http://azaleos.com>]
Sent: Tuesday, August 28, 2012 11:09 AM
To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
Subject: RE: Expanding cluster to include a new DR datacenter
So in an interesting turn of events, this works on my other 4 keyspaces but
just not this 'EBonding' one which will not recognize the changes. I can
probably get around this by dropping and re-creating this keyspace since its
uptime is not too important for us.
[default@AlertStats] describe AlertStats;
Keyspace: AlertStats:
Replication Strategy: org.apache.cassandra.locator.NetworkTopologyStrategy
Durable Writes: true
Options: [Fisher:3]
From: Mohit Anchlia [mailto:mohitanch...@gmail.com]
Sent: Monday, August 27, 2012 3:50 PM
To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
Subject: Re: Expanding cluster to include a new DR datacenter
Can you describe your schema again with TierPoint in it?
On Mon, Aug 27, 2012 at 3:22 PM, Bryce Godfrey
<bryce.godf...@azaleos.com<mailto:bryce.godf...@azaleos.com>> wrote:
Same results. I restarted the node also to see if it just wasn't picking up
the changes and it still shows Simple.
When I specify the DC for strategy_options I should be using the DC name from
properfy file snitch right? Ours is "Fisher" and "TierPoint" so that's what I
used.
From: Mohit Anchlia
[mailto:mohitanch...@gmail.com<mailto:mohitanch...@gmail.com>]
Sent: Monday, August 27, 2012 1:21 PM
To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
Subject: Re: Expanding cluster to include a new DR datacenter
In your update command is it possible to specify RF for both DC? You could just
do DC1:2, DC2:0.
On Mon, Aug 27, 2012 at 11:16 AM, Bryce Godfrey
<bryce.godf...@azaleos.com<mailto:bryce.godf...@azaleos.com>> wrote:
Show schema output show the simple strategy still
[default@unknown] show schema EBonding;
create keyspace EBonding
with placement_strategy = 'SimpleStrategy'
and strategy_options = {replication_factor : 2}
and durable_writes = true;
This is the only thing I see in the system log at the time on all the nodes:
INFO [MigrationStage:1] 2012-08-27 10:54:18,608 ColumnFamilyStore.java (line
659) Enqueuing flush of Memtable-schema_keyspaces@1157216346(183/228
serialized/live bytes, 4 ops)
INFO [FlushWriter:765] 2012-08-27 10:54:18,612 Memtable.java (line 264) Writing
Memtable-schema_keyspaces@1157216346(183/228 serialized/live bytes, 4 ops)
INFO [FlushWriter:765] 2012-08-27 10:54:18,627 Memtable.java (line 305)
Completed flushing
/opt/cassandra/data/system/schema_keyspaces/system-schema_keyspaces-he-34817-Data.db
(241 bytes) for commitlog p$
Should I turn the logging level up on something to see some more info maybe?
From: aaron morton
[mailto:aa...@thelastpickle.com<mailto:aa...@thelastpickle.com>]
Sent: Monday, August 27, 2012 1:35 AM
To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
Subject: Re: Expanding cluster to include a new DR datacenter
I did a quick test on a clean 1.1.4 and it worked
Can you check the logs for errors ? Can you see your schema change in there ?
Also what is the output from show schema; in the cli ?
Cheers
-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com<http://www.thelastpickle.com/>
On 25/08/2012, at 6:53 PM, Bryce Godfrey
<bryce.godf...@azaleos.com<mailto:bryce.godf...@azaleos.com>> wrote:
Yes
[default@unknown] describe cluster;
Cluster Information:
Snitch: org.apache.cassandra.locator.PropertyFileSnitch
Partitioner: org.apache.cassandra.dht.RandomPartitioner
Schema versions:
9511e292-f1b6-3f78-b781-4c90aeb6b0f6: [10.20.8.4, 10.20.8.5, 10.20.8.1,
10.20.8.2, 10.20.8.3]
From: Mohit Anchlia
[mailto:mohitanchlia@<mailto:mohitanchlia@>gmail.com<http://gmail.com/>]
Sent: Friday, August 24, 2012 1:55 PM
To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
Subject: Re: Expanding cluster to include a new DR datacenter
That's interesting can you do describe cluster?
On Fri, Aug 24, 2012 at 12:11 PM, Bryce Godfrey
<bryce.godf...@azaleos.com<mailto:bryce.godf...@azaleos.com>> wrote:
So I'm at the point of updating the keyspaces from Simple to NetworkTopology
and I'm not sure if the changes are being accepted using Cassandra-cli.
I issue the change:
[default@EBonding] update keyspace EBonding
... with placement_strategy =
'org.apache.cassandra.locator.NetworkTopologyStrategy'
... and strategy_options={Fisher:2};
9511e292-f1b6-3f78-b781-4c90aeb6b0f6
Waiting for schema agreement...
... schemas agree across the cluster
Then I do a describe and it still shows the old strategy. Is there something
else that I need to do? I've exited and restarted Cassandra-cli and it still
shows the SimpleStrategy for that keyspace. Other nodes show the same
information.
[default@EBonding] describe EBonding;
Keyspace: EBonding:
Replication Strategy: org.apache.cassandra.locator.SimpleStrategy
Durable Writes: true
Options: [replication_factor:2]
From: Bryce Godfrey
[mailto:bryce.godf...@azaleos.com<mailto:bryce.godf...@azaleos.com>]
Sent: Thursday, August 23, 2012 11:06 AM
To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
Subject: RE: Expanding cluster to include a new DR datacenter
Thanks for the information! Answers my questions.
From: Tyler Hobbs [mailto:ty...@datastax.com]
Sent: Wednesday, August 22, 2012 7:10 PM
To: user@cassandra.apache.org<mailto:user@cassandra.apache.org>
Subject: Re: Expanding cluster to include a new DR datacenter
If you didn't see this particular section, you may find it
useful:http://www.datastax.com/docs/1.1/operations/cluster_management#adding-a-data-center-to-a-cluster
Some comments inline:
On Wed, Aug 22, 2012 at 3:43 PM, Bryce Godfrey
<bryce.godf...@azaleos.com<mailto:bryce.godf...@azaleos.com>> wrote:
We are in the process of building out a new DR system in another Data Center,
and we want to mirror our Cassandra environment to that DR. I have a couple
questions on the best way to do this after reading the documentation on the
Datastax website. We didn't initially plan for this to be a DR setup when
first deployed a while ago due to budgeting, but now we need to. So I'm just
trying to nail down the order of doing this as well as any potential issues.
For the nodes, we don't plan on querying the servers in this DR until we fail
over to this data center. We are going to have 5 similar nodes in the DR,
should I join them into the ring at token+1?
Join them at token+10 just to leave a little space. Make sure you're using
LOCAL_QUORUM for your queries instead of regular QUORUM.
All keyspaces are set to the replication strategy of SimpleStrategy. Can I
change the replication strategy after joining the new nodes in the DR to
NetworkTopologyStategy with the updated replication factor for each dr?
Switch your keyspaces over to NetworkTopologyStrategy before adding the new
nodes. For the strategy options, just list the first dc until the second is up
(e.g. {main_dc: 3}).
Lastly, is changing snitch from default of SimpleSnitch to RackInferringSnitch
going to cause any issues? Since its in the Cassandra.yaml file I assume a
rolling restart to pick up the value would be ok?
This is the first thing you'll want to do. Unless your node IPs would
naturally put all nodes in a DC in the same rack, I recommend using
PropertyFileSnitch, explicitly using the same rack. (I tend to prefer PFSnitch
regardless; it's harder to accidentally mess up.) A rolling restart is
required to pick up the change. Make sure to fill out
cassandra-topology.properties first if using PFSnitch.
This is all on Cassandra 1.1.4, Thanks for any help!
--
Tyler Hobbs
DataStax<http://datastax.com/>
