Health Check for Primary and Secondary Nodes
Cluster Status
Read this section for all necessary information about displaying your cluster’s status.
New keyword CLUSTER is available for the following utility command: ADAOPR ... DISPLAY=CLUSTER
Sample output in case of success, all nodes of the cluster are in status SYNCED:
[saguser@ADACLU41 softwareag]$ adaopr dbid=141 disp=clu
%ADAOPR-I-STARTED, 21-DEC-2021 14:35:37, Version d.d.d.d (Linux 64Bit)
Database 141, startup at 21-DEC-2021 13:46:58
ADANUC Version d.d.d.d, PID 11371
ADANUC Version d.d.d.d
Database 141 Cluster on 21-DEC-2021 14:35:36
Cluster UUID 5591acaa-46f8-11ec-a313-0390244aecca
view was last updated at sequence number 116
cluster is at sequence number 116
3 Node(s) Primary component of the cluster
NAME ADATCP STATUS
ADACLU42-55142 adatcp://ADACLU42:56142 SYNCED
ADACLU43-55143 adatcp://ADACLU43:56143 SYNCED
ADACLU41-55141 adatcp://ADACLU41:56141 SYNCED
Primary node: ADACLU42-55142
Current node: ADACLU41-55141
Status of this node: Synced
%ADAOPR-I-TERMINATED, 21-DEC-2021 14:35:37, elapsed time: 00:00:00
The unique cluster identifier Cluster UUID (5591acaa-46f8-11ec-a313-0390244aecca) is allocated to the cluster and used for identification. For more information, see Setting Up a Three-Node Cluster.
Sequence number 116 identifies the number of database transactions and node changes.
3 Node(s) are identified, which are currently part of the primary component of the cluster.
The membership list shown in the table consists of three columns: CLUSTER_NODE_NAME, CLIENT_CONNECTION_STRING, and NODE_STATUS.
The Name of the nodes is generated while setting up the cluster, or can be allocated.
The host and port are shown in ADATCP and are the entry point from the client's perspective in the DB mapping.
The Status is shown in the last column. For more information about the possible statuses, see Cluster Framework: Replication > Node States.
The Primary node (ADACLU42-55142) is identified, which is the only node allowed to accept update commands.
Current node identifies the node on which the utility command ADAOPR ... DISPLAY=CLUSTER is running.
Health Check
To check connectivity for a port on a remote host where nc (netcat) command is not available due to security restrictions , you can use a command provided by bash (command language interpreter) instead:
</dev/tcp/<host>/<port>
Note:
In case of problems (port not in use, restricted firewall settings, ...) following message will be returned:
[saguser@ADACLU41 softwareag]$ </dev/tcp/adaclu42/55142
-bash: connect: Connection refused
-bash: /dev/tcp/adaclu42/55142: Connection refused
To check if someone is already using a port on a local host, you can run ss -tulpn | grep <port>
Sample output:
[saguser@ADACLU42 softwareag]$ ss -tulpn | grep 55142
tcp LISTEN 0 128 *:55142 *:* users:(("adanuc.bin",pid=19383,fd=9))