MySQL Cluster Manager 9.3.0 User Manual
Testing and performing the migration of a standalone MySQL NDB Cluster into MySQL Cluster Manager consists of the following steps:
Perform a test run of the proposed import using
import cluster with the
--dryrun
option. When this option is used, MySQL Cluster Manager checks for
mismatched configuration attributes, missing or invalid
processes or hosts, missing or invalid PID files, and
other errors, and warns of any it finds, without actually
performing any migration of processes or data (the step
only works if you have
created the
mcmd user on the cluster's mysqld nodes):
mcm> import cluster --dryrun newcluster;
If errors occur, correct them, and repeat the dry run shown in the previous step until it returns no more errors. The following list contains some common errors you may encounter, and their likely causes:
MySQL Cluster Manager requires a specific MySQL user and privileges to
manage SQL nodes. If the mcmd MySQL
user account is not set up properly, you may see
No access for user...,
Incorrect grants for user...,
or possibly other errors. Follow the instructions
given in
this
step in
Section 4.5.2.1, “Preparing the Standalone Cluster for Migration”
to remedy the issue.
As described previously, each cluster process (other
than a process whose type is
ndbapi) being brought under MySQL Cluster Manager
control must have a valid PID file. Missing, misnamed,
or invalid PID files can produce errors such as
PID file does not exist for
process..., PID ... is not
running ..., and PID ... is
type .... See
Section 4.5.2.2, “Verify All Cluster Process PID Files”.
Process version mismatches can also produce seemingly random errors whose cause can sometime prove difficult to track down. Ensure that all nodes are supplied with the correct release of the MySQL NDB Cluster software, and that it is the same release and version of the software.
Each data node angel process in the standalone cluster
must be killed prior to import. A running angel
process can cause errors such as Angel
process pid exists
... or Process
pid is an angel process for
.... If you see such errors, proceed to
the next step if these are the only errors you get.
The angel processes and the data node PIDs will be
taken care of by the
--remove-angel
option used with the import
cluster command at the last step of the
import process.
The number of processes, their types, and the hosts
where they reside in the standalone cluster must be
reflected accurately when creating the target site,
package, and cluster for import. Otherwise, you may
get errors such as Process
id reported
# processes
..., Process
id ... does not match
configured process ..., Process
id not configured
..., and Process
id does not match
configured process .... See
Section 4.5.2.3, “Creating and Configuring the Target Cluster”.
Other factors that can cause specific errors include processes in the wrong state, processes that were started with unsupported command-line options (see Section 4.5.2.3, “Creating and Configuring the Target Cluster” for details) or without required options, and processes having the wrong process ID, or using the wrong node ID.
When import cluster
--dryrun no longer warns of any errors, you can
perform the import with the import
cluster command, this time omitting the
--dryrun
option. Use the
--remove-angel
option for the
import
cluster command, which kills the angel processes
for the data nodes and adjusts the data nodes' PID files
to contain the data node processes' own PIDs before
importing the cluster:
mcm> import cluster --remove-angel newcluster;
+-------------------------------+
| Command result |
+-------------------------------+
| Cluster imported successfully |
+-------------------------------+
1 row in set (5.58 sec)
You can check that the wild cluster has now been imported, and is now under management of MySQL Cluster Manager:
mcm> show status -r newcluster;
+--------+----------+----------------+---------+-----------+------------+
| NodeId | Process | Host | Status | Nodegroup | Package |
+--------+----------+----------------+---------+-----------+------------+
| 50 | ndb_mgmd | 198.51.100.102 | running | | newpackage |
| 2 | ndbd | 198.51.100.103 | running | 0 | newpackage |
| 3 | ndbd | 198.51.100.104 | running | 0 | newpackage |
| 51 | mysqld | 198.51.100.102 | running | | newpackage |
| 52 | ndbapi | * | added | | |
+--------+----------+----------------+---------+-----------+------------+
5 rows in set (0.01 sec)