The following semi-automated process can be used to migrate from MemSQL Ops to SingleStore DB Tools.
Command output examples are provided. Note that, as they are representative samples, what is displayed on your screen may vary.
Unless explicitly stated otherwise, perform all of the following steps on/from the Master Aggregator.
In the commands provided, replace all instances of content in angle brackets with the referenced substitute. Note that multiple instances may need to be replaced in a single command.
In some cases, a script may require non-password access to all hosts in the cluster.
Review Current Cluster
Use MemSQL Ops to validate the SingleStore DB cluster health. Confirm that all nodes are listed, online, healthy, and are running MemSQL 6.7 or later. Make sure that the nodes meet these requirements before proceeding with the migration.
memsql-ops memsql-list
****
ID Agent Id Process State Cluster State Role Host Port Version
44CDE71 A0c8a89 RUNNING CONNECTED MASTER 10.0.0.98 3306 x.x
3FD3FCF Aa5eab9 RUNNING CONNECTED AGGREGATOR 10.0.0.133 3306 x.x
9C0841F A04f65f RUNNING CONNECTED LEAF 10.0.0.236 3306 x.x
9A551DA A5f0572 RUNNING CONNECTED LEAF 10.0.0.136 3306 x.x
Confirm Connectivity
Confirm that memsql-ops agent-ssh can be used to SSH (open a secure shell) into each host in the cluster. Although this command is used to SSH into hosts, the initial output of the command can be used to check whether SSH has been configured on all hosts.
Note: After invoking the following interactive prompt, exit the command immediately by using Control-C without actually connecting to the hosts via SSH.
sudo memsql-ops agent-ssh
****
Index ID Host Port Role State Version Has Credential
1 Aeea1ec 10.0.0.98 9000 PRIMARY ONLINE x.x No
2 A005a87 10.0.0.133 9000 FOLLOWER ONLINE x.x Yes
3 Aa9367f 10.0.0.236 9000 FOLLOWER ONLINE x.x Yes
4 Ad90aba 10.0.0.136 9000 FOLLOWER ONLINE x.x Yes
In the output displayed above, only the main host where the Ops primary agent runs should reflect No for Has Credential. For all other hosts, it is strongly recommended to set an SSH credential before proceeding with the migration. SingleStore DB Toolbox must SSH into each host to run commands. This means that if the SSH credentials are not set, you will be prompted for a username and a password for every host in the cluster, for every SingleStore DB Toolbox command that you run. To configure ssh keys for each host, run the memsql-ops agent-set-credential command (see instructions).
Alternatively, use the following script to automate this process. While executing the script, make sure to provide the ssh keys where applicable.
memsql-ops agent-list -q | xargs -n 1 memsql-ops agent-set-credential -i </key-file/including/path>
Enable Manual Control
Enable manual control of the MemSQL cluster to prevent MemSQL Ops from interfering with the SingleStore DB Toolbox install.
memsql-ops cluster-manual-control --enable
****
The cluster is now under manual control. We will not automatically restart stopped nodes, update license files, etc.
MemSQL Ops will not automatically restart nodes that fail during the migration. While SingleStore DB Toolbox has been installed, no hosts or nodes are known to it yet. Hence, nodes will not be auto-restarted if they fail while the migration is underway.
Add a License
If you are using a license with an earlier format (called the Odin license), update it to the latest license (called the Freya license) obtained from the SingleStore Customer Portal. To verify the format of the current license, use the command below:
memsql-ops license-list -j
The license marked as best is the one in current use, and the expected format of the license is <HASH>==. If the current license does not match the expected format, request a new license in the Customer Portal and add it using the command below:
memsql-ops license-add --license-key <license>
****
Successfully added license.
Set root Password
Set the root password for all nodes in the cluster. Substitute the Master Aggregator’s password for <password> in the following command.
memsql-ops memsql-list -q | xargs -n 1 \
memsql-ops memsql-update-root-password --no-confirmation -p <password>
Generate Migration File
Run the following command to generate a cluster migration YAML file that will pass the cluster information from MemSQL Ops to SingleStore DB Toolbox. The cluster migration YAML file will be used in the command in the next step.
sudo memsql-ops migration-setup
****
Check succeeded: All nodes on MemSQL version x.x
Check succeeded: All nodes online and connected
Check succeeded: All nodes with supported license version
All checks passed. Migration configuration file written to /var/lib/memsql-ops/data/cache/migration_config.yml
Add root Password
Run the following command to add the root_password to the end of the cluster migration YAML file. Substitute the Master Aggregator’s password for <password>.
echo 'root_password: <password>' >> <cluster_file>
Deploy Migration File
Use the cluster migration YAML generated by the previous command.
sdb-deploy setup-cluster --cluster-file <cluster_file>
✓ Connection successful to 10.0.0.136
✓ Connection successful to 10.0.0.133
✓ Connection successful to 10.0.0.236
sdb-deploy will perform the following actions:
· Register Hosts
- Host: 10.0.0.98
+ Localhost: true
- Host: 10.0.0.136
+ Localhost: false
+ Port: 22
+ Username: <user>
- Host: 10.0.0.133
+ Localhost: false
+ Port: 22
+ Username: <user>
- Host: 10.0.0.236
+ Localhost: false
+ Port: 22
+ Username: <user>
· Install MemSQL Server
- Install memsql-server x.x on 10.0.0.98
- Install memsql-server x.x on 10.0.0.136
- Install memsql-server x.x on 10.0.0.133
- Install memsql-server x.x on 10.0.0.236
· Register Node
- On Host: 10.0.0.136
+ Run 'memsqlctl register-node --memsql-config /var/lib/memsql/leaf-3306-MI2fc1915e/memsql.cnf --datadir /var/lib/memsql/leaf-3306-MI2fc1915e/data --plancachedir /var/lib/memsql/leaf-3306-MI2fc1915e/plancache --tracelogsdir /var/lib/memsql/leaf-3306-MI2fc1915e/tracelogs --port 3306'
- On Host: 10.0.0.133
+ Run 'memsqlctl register-node --memsql-config /var/lib/memsql/child-3306-MIb4668da6/memsql.cnf --datadir /var/lib/memsql/child-3306-MIb4668da6/data --plancachedir /var/lib/memsql/child-3306-MIb4668da6/plancache --tracelogsdir /var/lib/memsql/child-3306-MIb4668da6/tracelogs --port 3306'
- On Host: 10.0.0.236
+ Run 'memsqlctl register-node --memsql-config /var/lib/memsql/leaf-3306-MId88e2bc0/memsql.cnf --datadir /var/lib/memsql/leaf-3306-MId88e2bc0/data --plancachedir /var/lib/memsql/leaf-3306-MId88e2bc0/plancache --tracelogsdir /var/lib/memsql/leaf-3306-MId88e2bc0/tracelogs --port 3306'
- On Host: 10.0.0.98
+ Run 'memsqlctl register-node --memsql-config /var/lib/memsql/master-3306-MI436853b1/memsql.cnf --datadir /var/lib/memsql/master-3306-MI436853b1/data --plancachedir /var/lib/memsql/master-3306-MI436853b1/plancache --tracelogsdir /var/lib/memsql/master-3306-MI436853b1/tracelogs --port 3306'
· After executing the above actions the cluster is going to be in the following state:
- 4 Registered nodes
Would you like to continue? [y/N]: y
✓ Registered hosts
✓ Installed memsql-server<version> on host 10.0.0.236 (1/4)
✓ Installed memsql-server<version> on host 10.0.0.98 (2/4)
✓ Installed memsql-server<version> on host 10.0.0.136 (3/4)
✓ Installed memsql-server<version> on host 10.0.0.133 (4/4)
✓ Successfully installed on 4 hosts
✓ Successfully registered nodes
✓ No Nodes to Create
✓ No Leaves to add
✓ No Aggregators to add
The Final Cluster State
Hosts
+----------------+------------+---------------------------+---------------+
| Host | Local Host | SSH address | Identity File |
+----------------+------------+---------------------------+---------------+
| 10.0.0.98 | Yes | | |
| 10.0.0.133 | No | <user>@10.0.0.133:22 | |
| 10.0.0.136 | No | <user>@10.0.0.136:22 | |
| 10.0.0.236 | No | <user>@10.0.0.236:22 | |
+----------------+------------+---------------------------+---------------+
Nodes
+------------+------------+----------------+------+---------------+--------------+---------+----------------+--------------------+--------------+
| MemSQL ID | Role | Host | Port | Process State | Connectable? | Version | Recovery State | Availability Group | Bind Address |
+------------+------------+----------------+------+---------------+--------------+---------+----------------+--------------------+--------------+
| 6C1E8E88A6 | Master | 10.0.0.98 | 3306 | Running | True | x.x | Online | | 0.0.0.0 |
| BE9E87CCE3 | Aggregator | 10.0.0.133 | 3306 | Running | True | x.x | Online | | 0.0.0.0 |
| 8419072D05 | Leaf | 10.0.0.136 | 3306 | Running | True | x.x | Online | 2 | 0.0.0.0 |
| 36B777507F | Leaf | 10.0.0.236 | 3306 | Running | True | x.x | Online | 1 | 0.0.0.0 |
+------------+------------+----------------+------+---------------+--------------+---------+----------------+--------------------+--------------+
End: See Deploy Cluster Migration File Output
Confirm Registered Hosts
Use SingleStore DB Toolbox to confirm that all hosts have been registered.
sdb-toolbox-config list-hosts
****
+------------+------------+-------------+--------------------------+
| Host | Local Host | SSH address | Identity File |
+------------+------------+-------------+--------------------------+
| 10.0.0.98 | No | 10.0.0.98 | /home/<user>/.ssh/id_rsa |
| 10.0.0.133 | No | 10.0.0.133 | /home/<user>/.ssh/id_rsa |
| 10.0.0.136 | No | 10.0.0.136 | /home/<user>/.ssh/id_rsa |
| 10.0.0.236 | No | 10.0.0.236 | /home/<user>/.ssh/id_rsa |
+------------+------------+-------------+--------------------------+
Confirm Registered Nodes
Use SingleStore DB Toolbox to confirm that all nodes have been registered.
sdb-admin list-nodes
****
+------------+------------+------------+------+---------------+--------------+---------+----------------+--------------------+
| MemSQL ID | Role | Host | Port | Process State | Connectable? | Version | Recovery State | Availability Group |
+------------+------------+------------+------+---------------+--------------+---------+----------------+--------------------+
| 0EAE75B920 | Master | 10.0.0.98 | 3306 | Running | True | x.x | Online | |
| 35B6AA0317 | Aggregator | 10.0.0.133 | 3306 | Running | True | x.x | Online | |
| B964A18F18 | Leaf | 10.0.0.136 | 3306 | Running | True | x.x | Online | 1 |
| 1A8EDD42BB | Leaf | 10.0.0.236 | 3306 | Running | True | x.x | Online | 2 |
+------------+------------+------------+------+---------------+--------------+---------+----------------+--------------------+
Restart Nodes
Use SingleStore DB Toolbox to restart all nodes. This transfers cluster control to SingleStore DB Toolbox. After this step is completed, SingleStore DB Toolbox will manage the cluster, including automatically starting any offline nodes.
sdb-admin restart-node --all
For high-availability clusters, you may include the --online option to perform a rolling restart of the cluster, which allows the workload to continue while the nodes are restarted.
sdb-admin restart-node --all --online
While this step is underway, the node state may be registered incorrectly in SingleStore DB Toolbox (as displayed by sdb-admin list-nodes). You can check the actual cluster state with SHOW LEAVES or SHOW AGGREGATORS executed in a database connection to the Master Aggregator. When this step is completed, SingleStore DB Toolbox should show the node state accurately.
Toolbox is about to perform the following actions:
· Restart all nodes in the cluster
Would you like to continue? [y/N]: y
✓ Stopped Master node on 10.0.0.98 (1/1)
✓ Successfully stopped Master node on 1 host
✓ Stopped Master node
✓ Stopped Aggregator nodes on 10.0.0.133 (1/1)
✓ Successfully stopped Aggregator nodes on 1 host
✓ Stopped Aggregator node
✓ Stopped Leaf nodes on 10.0.0.136 (1/2)
✓ Stopped Leaf nodes on 10.0.0.236 (2/2)
✓ Successfully stopped Leaf nodes on 2 hosts
✓ Stopped Leaf nodes
✓ Started Leaf nodes on 10.0.0.236 (1/2)
✓ Started Leaf nodes on 10.0.0.136 (2/2)
✓ Successfully started Leaf nodes on 2 hosts
✓ Successfully connected to Leaf nodes
✓ Started Aggregator nodes on 10.0.0.133 (1/1)
✓ Successfully started Aggregator nodes on 1 host
✓ Successfully connected to Aggregator node
✓ Started Master node on 10.0.0.98 (1/1)
✓ Successfully started Master node on 1 host
✓ Successfully connected to Master node
Operation completed successfully
End: See Restart Nodes Output
Confirm Node Restart
Confirm that all nodes have restarted.
sdb-admin list-nodes
****
+------------+------------+------------+------+---------------+--------------+---------+----------------+--------------------+
| MemSQL ID | Role | Host | Port | Process State | Connectable? | Version | Recovery State | Availability Group |
+------------+------------+------------+------+---------------+--------------+---------+----------------+--------------------+
| D785AA80D7 | Master | 10.0.0.98 | 3306 | Running | True | x.x | Online | |
| 9098564B01 | Aggregator | 10.0.0.133 | 3306 | Running | True | x.x | Online | |
| 2189856FC2 | Leaf | 10.0.0.136 | 3306 | Running | True | x.x | Online | 2 |
| 3094B68557 | Leaf | 10.0.0.236 | 3306 | Running | True | x.x | Online | 1 |
+------------+------------+------------+------+---------------+--------------+---------+----------------+--------------------+
Unmonitor Nodes
Once SingleStore DB Toolbox is managing the MemSQL cluster, the competing MemSQL Ops management system must be uninstalled.
Use MemSQL Ops to list all running nodes.
memsql-ops memsql-list
****
ID Agent Id Process State Cluster State Role Host Port Version
44CDE71 A0c8a89 RUNNING CONNECTED MASTER 10.0.0.98 3306 x.x
3FD3FCF Aa5eab9 RUNNING CONNECTED AGGREGATOR 10.0.0.133 3306 x.x
9C0841F A04f65f RUNNING CONNECTED LEAF 10.0.0.236 3306 x.x
9A551DA A5f0572 RUNNING CONNECTED LEAF 10.0.0.136 3306 x.x
Use MemSQL Ops to stop monitoring each MemSQL node.
Use the IDs from the ID column in the MemSQL Ops output.
Do not remove the leaf nodes if prompted.
Main Host
Run the following command on the main host, which is usually the host of the Master Aggregator.
memsql-ops memsql-unmonitor 44CDE71
****
2019-07-02 16:30:23: J9fe705 [INFO] Stopping monitoring for MemSQL node ABECB9CFBB84C5369982BE10A85EC050D20486B0
2019-07-02 16:30:23: J9fe705 [INFO] No longer monitoring MemSQL node ABECB9CFBB84C5369982BE10A85EC050D20486B0
Child Aggregator
memsql-ops memsql-unmonitor 3FD3FCF
****
2019-07-02 16:30:54: J6fb0f3 [INFO] Stopping monitoring for MemSQL node 4DF1BC43819C21D33B6D6AAE02C8851F40709FDF
2019-07-02 16:30:54: J6fb0f3 [INFO] No longer monitoring MemSQL node 4DF1BC43819C21D33B6D6AAE02C8851F40709FDF
Leaf Node 1
memsql-ops memsql-unmonitor 9C0841F
****
Would you additionally like to remove the leaf node from the MemSQL cluster? (You can specify this behavior with --remove-leaf.) [y/n] n
2019-07-02 16:31:22: J2eae2d [INFO] Stopping monitoring for MemSQL node AF1C3A169BFE4FD792163909BDB592C65D0E37AF
2019-07-02 16:31:22: J2eae2d [INFO] No longer monitoring MemSQL node AF1C3A169BFE4FD792163909BDB592C65D0E37AF
Note: If a leaf is removed unintentionally, connect to the database and run ADD LEAF to add it back to the cluster: For example, on the Master Aggregator: memsql> ADD LEAF 'root'@'<<leaf node IP>>':3307
Leaf Node 2
memsql-ops memsql-unmonitor 9A551DA
****
Would you additionally like to remove the leaf node from the MemSQL cluster? (You can specify this behavior with --remove-leaf.) [y/n] n
2019-07-02 16:32:01: J52843c [INFO] Stopping monitoring for MemSQL node 143B60B39072A9E9C16D2D8ACC16E6997286079E
2019-07-02 16:32:01: J52843c [INFO] No longer monitoring MemSQL node 143B60B39072A9E9C16D2D8ACC16E6997286079E
Note: If a leaf is removed unintentionally, connect to the database and run ADD LEAF to add it back to the cluster: For example, on the Master Aggregator: memsql> ADD LEAF 'root'@'<<leaf node IP>>':3307
End: Unmonitor Remaining Nodes
Confirm Unmonitored Nodes
Use MemSQL Ops to confirm that all MemSQL nodes are no longer monitored.
memsql-ops memsql-list
****
No MemSQL nodes were found.
Remove MemSQL Ops
sudo memsql-ops agent-uninstall --uninstall-ops-only --all
The --uninstall-ops-only flag ensures that the MemSQL Ops agent will be uninstalled without deleting any node data.
This will completely delete all MemSQL Ops agents in the cluster, including this one. This operation will delete all MemSQL Ops data in the cluster and cannot be undone.
If you want to delete all MemSQL Ops agents, please type the word DELETE: DELETE
2019-09-06 13:58:23: J91ad35 [INFO] Deleting MemSQL Ops agent Ae9f037643ccf4b5fb3b0c03f2dd0da58
2019-09-06 13:58:23: J4cc070 [INFO] Deleting MemSQL Ops agent Ae2838b5fd2164d3a8691ad71227beee3
2019-09-06 13:58:23: Jfb011f [INFO] Deleting MemSQL Ops agent Afea25a7c3e184241acdf5296f429298d
2019-09-06 13:58:27: J4cc070 [INFO] Successfully deleted MemSQL Ops agent Ae2838b5fd2164d3a8691ad71227beee3
2019-09-06 13:58:27: Jfb011f [INFO] Successfully deleted MemSQL Ops agent Afea25a7c3e184241acdf5296f429298d
2019-09-06 13:58:27: J91ad35 [INFO] Successfully deleted MemSQL Ops agent Ae9f037643ccf4b5fb3b0c03f2dd0da58
WARNING: An unmonitored MemSQL node may still exist on this machine. It had host 172.16.212.165 and port 3306 the last time MemSQL Ops connected to it.
Stopping MemSQL Ops
Waiting up to 60 seconds for a clean exit.
Done.
Successfully uninstalled MemSQL Ops
End: See Remove MemSQL Ops Output
