To mirror volumes between unsecure clusters, start by editing the mapr-clusters.conf
file on the source volume's cluster and create an
entry for each additional cluster that hosts a mirror of the volume. The entry must list
the cluster's name, followed by a space-separated list of hostnames and ports for the
cluster's CLDB nodes. In addition, use the secure
parameter to specify
whether the clusters are secure or non-secure. See Configuring Secure Clusters for Cross-Cluster Mirroring and Replication for more information about
generating tickets for secure clusters. Note: When mirroring between clusters, servers in
one cluster cannot use the same IP addresses as servers in the other cluster. For
example, if node A in cluster A has a private IP address 10.10.20.29, no server in
cluster B can have the same private IP address. Also, all the servers in one cluster
must be able to reach all the servers in the other cluster and vice versa. For example,
suppose 10.10.20.29 is the only IP address used by node A in cluster A; then all servers
in cluster B should be able to reach the IP address 10.10.20.29.
To set up
cross-mirroring between unsecure clusters:
-
Review the requirements for Creating Remote Mirrors
before you begin.
-
On each cluster, make a note of the cluster name and CLDB nodes (the first line in
mapr-clusters.conf
)
-
On each webserver and CLDB node, add the remote cluster's CLDB nodes to
/opt/mapr/conf/mapr-clusters.conf
, using the following format:
clustername1 <CLDB> <CLDB> <CLDB>
[ clustername2 <CLDB> <CLDB> <CLDB> ]
[ ... ]
For example, suppose you have a cluster, clusterA,
with two CLDB
nodes, nodeA
and nodeB
. Now you want to add a
second cluster called clusterB
with CLDB nodes
nodeC
and nodeD
. Edit the
mapr-clusters.conf
file and add the line for
clusterB
as shown:
clusterA nodeA:7222 nodeB:7222
clusterV nodeC:7222 nodeD:7222
Warning: You must include the port number in the CLDB hostname notation.
Here:
- First line contains cluster name and CLDB nodes of cluster A (the local
cluster)
- Second line contains cluster name and CLDB nodes of cluster B (the remote
cluster)
The
mapr-clusters.conf
file for cluster B with 2 CLDB nodes
(
nodeC
and
nodeD
) would look like this:
clusterB nodeC:7222 nodeD:7222
clusterA nodeA:7222 nodeB:7222
By creating additional entries in the mapr-clusters.conf
file,
you can mirror from one cluster to several others.
-
Set
secure=false
if both clusters are not secure. If both the
clusters are secure, see Configuring Secure Clusters for Cross-Cluster Mirroring and Replication for more
information.
Warning: Mirroring only works between two secure clusters or between two
non-secure clusters. Mirroring does not work when one cluster is secure and the
other is non-secure.
-
On each cluster, restart the
mapr-apiserver
service on all nodes
where it is running.