I am new to cassandra and would like some help on restoring snapshots from 3 node Cassandra cluster to a new 6 node cluster.
We have few keyspaces and would like to copy data from dev to production.
Thanks in advance.
The easiest way is to use the sstableloader tool that is bundled with Cassandra. You can find it in %installdir%/bin/sstableloader.
You will first need to re-create the schema on your new cluster:
dump the schema for the keyspace you want to transfer from your original cluster using cqlsh -e 'DESC KEYSPACE mykeyspace;' > mykeyspace.cql
load it into your new cluster using cqlsh -f mykeyspace.cql.
(optional) If you new cluster will have a different replication configuration you'll need to modify it manually after loading the schema. (ALTER KEYSPACE mykeyspace WITH REPLICATION = ...;)
Once that's done, you can start bulk-loading the SSTables from your keyspace snapshots into the new cluster:
sstableloader --nodes 10.0.0.1,10.0.0.2 -f /etc/cassandra/cassandra.yaml /path/to/mykeyspace/snapshot/
Note that this might take a while if you have a lot of data to load. You should also run a full repair on the new cluster afterwards to ensure that the replicas are properly distributed.
Related
I have this case. We have 6 nodes DSE cluster and the task is to back it up, and restore all the keyspaces, tables and data into a new cluster. But this new cluster has only 4 nodes.
Is it possible to do this?
Yes, it is definitely possible to do this. This operation is more commonly referred to as "cloning" -- you are copying the data from one DataStax Enterprise (DSE) cluster to another.
There is a Cassandra utility called sstableloader which reads the SSTables and loads it to a cluster even when the destination cluster's topology is not identical to the source.
I have previously documented the procedure in How to migrate data in tables to a new Cassandra cluster which is also applicable to DSE clusters. Cheers!
I have 3 node cassandra cluster and I have a script which backup all of the keyspaces, but when it comes to restore on fresh cluster, data keyspaces restored correctly, but system_* keyspaces not.
So it is necessary to backup system keyspaces in cassandra?
You will need to backup the keyspace system_schema at the same time, as it will contain the definition of keyspaces, tables, and columns. The other system* keyspaces should be left untouched.
Fresh cluster makes own setup like token ranges etc based on configurations.you can restore the cluster on new cluster but you need to create schema and configuration same as old cluster. There is many ways to take backup and restore procedure based on requirements as below:-
https://docs.datastax.com/en/archived/cassandra/3.0/cassandra/operations/opsBackupRestore.html
I" have an existing cassandra cluster running in AWS. It has total 6 nodes in the same data center but in multiple regions. We are using cassandra version 2.2.8 in production. There are two existing keyspaces already present in the production environment. I want to add a new keyspace to the production cluster.
I am new to Cassandra so looking for following answers:
Can I add new keyspace in the existing production cluster without taking the cluster down?
Any best practices you would recommend to add the new keyspace to the existing cluster.
Possible steps to add new Keyspace?
I really appreciate your help!
Yes, you can add keyspaces online.
When you add a keyspace, you have to choose the Replication Factor. As you have AWS Multi Region, probably you are using Ec2MultiRegionSnitch as endpoint_snitch, right?
If you do, probably you configured dc_suffix=_XYZ and now you have your DCs like this: "us-east_XYZ" (See on nodetool status).
Then, you can use something like this:
CREATE KEYSPACE my_keysace
WITH REPLICATION = {
'class' : 'NetworkTopologyStrategy','us-east_XYZ' : 2, 'us-west_XYZ':2 }
AND DURABLE_WRITES = true
See docs: CREATE KEYSPACE
We have our current production cluster running on Cassandra 2.2.4
[cqlsh 5.0.1 | Cassandra 2.2.4 | CQL spec 3.3.1 | Native protocol v4]
We want to migrate this setup to a new cluster with DSE 5.0 without disturbing our current production.
What are the steps to do this, with zero/minimal downtime?
We want to have this as a separate cluster.
Can we use sstableloader from source to destination cluster and do a sstableupgrade at destination?
Should we stop compaction on the existing cluster, when running sstabloader?
How to transfer newly created sstables because of the production traffic?
Should we make application to write to both clusters, but only read from the old cluster, until new cluster is in sync with old cluster?
Should we run sstableloader from old data directory or from snapshot directory. What is the difference between the 2 approaches?
Setup your new cluster using DSE 5.0
Begin writing to both of your clusters
SCP your SSTables over from the old cluster to the new cluster
Use sstableloader, from your new cluster, on the SSTables you just copied to the new cluster.
Should we run sstableloader from old data directory or from snapshot directory. What is the difference between the 2 approaches?
Depends, the snapshots are exactly that, a snapshot of a specific state your cluster was in at some point in time. If you want the freshest data, use the SSTables currently in your data directory.
I'm trying use Datastax Enterprise for deploying database system
My cluster:
2 dse cassandra node
2 dse solr node
I created a keyspace by cqlsh on one node but I could not drop that keyspace from another nodes on cluster, unless drop from node creating keyspace. Anybody know why?
This sounds like https://issues.apache.org/jira/browse/CASSANDRA-5202
I have had to delete the data directory for the troubled key space in all nodes and restart DSE to fix.
Do you have the output from cqlsh on the node that won't allow you to drop the keyspace?
What version of DSE are you using?