gs_om

Background

gs_om, provided by MogDB, is used to maintain MogDB. You can use it to start and stop MogDB, query the MogDB status, query static configurations, query MogDB status details, generate static configuration file and dynamic configuration file, replace SSL certificates, query help information, and query the version number.

Prerequisites

Log in to the OS as the OS user omm to run the gs_om command.

Syntax

• Start MogDB.

  gs_om -t start [-h HOSTNAME] [-D dataDir] [--time-out=SECS] [--security-mode=MODE] [--cluster-number=None] [-l LOGFILE]

• Stop MogDB.

  gs_om -t stop [-h HOSTNAME] [-D dataDir]  [--time-out=SECS] [-m MODE] [-l LOGFILE]

• Restart MogDB.

  gs_om -t restart [-h HOSTNAME] [-D dataDir] [--time-out=SECS] [--security-mode=MODE] [-l LOGFILE] [-m MODE]

• Query the MogDB status.

  gs_om -t status [-h HOSTNAME] [-o OUTPUT] [--detail] [--all] [-l LOGFILE]

• Generate a static configuration file.

  gs_om -t generateconf -X XMLFILE [--distribute] [-l LOGFILE]
  gs_om -t generateconf --old-values=old --new-values=new [--distribute] [-l LOGFILE]

• Generate a dynamic configuration file. Perform this operation after the failover or switchover from the standby node to the primary node.

  gs_om -t refreshconf

• Display the static configurations.

  gs_om -t view [-o OUTPUT]

• Query the MogDB status details.

  gs_om -t query [-o OUTPUT]

• Replace SSL certificates.

  gs_om -t cert --cert-file=CERTFILE [-l LOGFILE]
  gs_om -t cert --rollback

• Enable or disable the Kerberos authentication in the cluster.

  gs_om -t kerberos -m [install|uninstall] -U USER [-l LOGFILE] [--krb-client|--krb-server]

• Display help information.

  gs_om -? | --help

• Display version information.

  gs_om -V | --version

Parameter Description

The gs_om tool can use the following types of parameters:

• Common parameters

  • -t

    Specifies the command types of gs_om.

    Value range: start, stop, status, generateconf, cert, view, query, refreshconf, and kerberos

  • -l

    Specifies a log file and its storage path.

    Default value: $GAUSSLOG/om/gs_om-YYYY-MM-DDhhmmss**.log** (default value for virtualip: /tmp/gs_virtualip/gs_om-YYYY-MM-DDhhmmss**.log**)

  • -?, --help

    Displays help information.

  • -V, --version

    Displays version information.

  • MogDB startup parameters

  • -h

    Specifies the name of the server to be started. Only one server can be started at a time.

    Value range: a server name

    If no server name is specified, MogDB is started.

  • -D

    Specifies the path of a specified node.

    Value range: a node path

    If the node path is not specified, the node path in the static file is used.

  • --time-out=SECS

    Specifies the timeout threshold. gs_om exits when times out. Unit: s

    Value range: a positive integer. The recommended value is 300.

    Default value: 300

  • --security-mode

    Specifies whether to start the database in secure mode.

    Value range: on: Start the database in secure mode. off: Not start the database in secure mode.

    The secure mode is disabled by default.

  • --cluster-number

    Specifies the version number of the kernel to run at boot time.

    Value range: Kernel version number.

• MogDB stop parameters

  • -h

    Specifies the name of the server where the instance to be stopped is located. Only one server can be stopped at a time.

    Value range: the name of the server where the instance is located

    If no server name is specified, MogDB is stopped.

  • -m, --mode=MODE

    Sets the stop mode.

    Value range: the following two stop modes are supported:

    • fast: The data of the primary and standby instance relationship is ensured to be consistent.
    • immediate: The data of the primary and standby instance relationship is not ensured to be consistent.

    Default value: fast

• --time-out=SECS

  Specifies the timeout threshold. gs_om exits when times out. Unit: s

  Value range: a positive integer. The recommended value is 300.

  Default value: 300

• Parameters for checking status

  Table 1 describes parameters in the query result.

  • -h

    Specifies the name of the server to be queried.

    Value range: a server name

    If no server name is specified, MogDB is queried.

  • --az

    Specify the name of the AZ to be queried, such as -az=AZ1.

    Value range: AZ name. If AZ name is not specified, it means to query all AZ.

  • -o

    Outputs status information to the specified output file.

    If the parameter is not output to the specified file, it is displayed on the screen.

  • --detail

    Displays detailed information. If the parameter is not specified, only a prompt is displayed indicating whether the server is normal.

    --all

    Displays information about all MogDB nodes.

• Parameters for generating the configuration file:

  • -X

    Selects the path of the MogDB configuration file.

    Value range: path of the clusterconfig.xml file.

  • --old-values=old

    The old values in static files that need to be modified.

    Value range: port, ip, hostname, you can enter multiple values, separated by commas.

  • --new-values=new

    The new value in the static file that needs to be modified.

    Value range: port, ip, hostname, multiple values can be entered, separated by commas, corresponding to old-values one-to-one.

  • --distribute

    Publishes the static configuration file to the installation directory of the MogDB instance.

• Parameters for enabling or disabling the Kerberos authentication in the cluster

  • -U

    Specifies a database cluster user.

    Value range: a database cluster deployment user

  • -m

    Specifies the operations to be performed.

    Value range:

    install: Enables the Kerberos authentication in a cluster is enabled.

    uninstall: Disables the Kerberos authentication in a cluster is disabled.

  • --krb-server: Installs the Kerberos server authentication.

  • --krb-client: Installs the Kerberos client authentication.

    Note: You need to use --krb-server to install the server authentication first. These two parameters are not required during the uninstallation because the server and client are uninstalled at the same time.

• Parameters for replacing SSL certificates

  • --cert-file

    Specifies the path of the local SSL certificate .zip package.

  • --rollback

    Rolls back the certificates to the last backup.

  • -L

    When setting this parameter, only the current node is performed.

Table 1 Status description

Field	Field Description	Field Value
cluster_state	MogDB status, which indicates whether MogDB is running properly.	- Normal: MogDB is available and the data has redundancy backup. All the processes are running and the primary/standby relationship is normal. - Unavailable: MogDB is unavailable. - Degraded: MogDB is available but the data does not have redundancy backup.
redistributing	Data redistribution status.	- Yes: MogDB is in data redistribution status. - No: MogDB is not in data redistribution status.
balanced	Load balancing status, which indicates whether a primary/standby switchover has occurred in the MogDB instance and made the host load unbalanced.	- Yes: The host loading is balanced in MogDB. - No: The host loading is not balanced in MogDB.
node	Host name.	Specifies the name of a host where an instance is located. If multiple AZs exist, the AZ IDs will be displayed.
node_ip	Host IP address.	Specifies the IP address of a host where an instance is located.
instance	Instance ID.	Specifies the instance ID.
state	Instance status.	- P: The initial role of the node is Primary. After the database is installed, the role does not change and is read from the system static file. - S: The initial role of the node is Standby. After the database is installed, the role does not change and is read from the system static file. - C: The initial role of the node is Cascade Standby. After the database is installed, the role does not change and is read from the system static file. - Primary: The instance is a primary instance. - Standby: The instance is a standby instance. - Cascade Standby: The instance is a cascaded standby instance. - Pending: The instance is in arbitration. - Unknown: The instance status is unknown. - Down: The instance is down.

Table 2 Feature IDs

Feature Name	ID	MogDB Product
Multi-value column	0	Basic edition
JSON	1	License control not supported
XML	2	Not supported
Data storage format ORC	3	Basic edition
One primary and multiple readable standbys on single-node	5	Invalid
Multidimensional collision and analysis (GPU acceleration)	7	Advanced feature
Full-text indexing	8	Basic edition
EXTENSION_CONNECTOR	9	Basic edition
EXPRESS_CLUSTER	12	Advanced edition
Cross-DC collaboration	13	Advanced edition
Figure	14	Not supported
Time sequence	15	Not supported
PostGIS interconnection	16	Basic edition
HA in MogDB (one primary and multiple standbys)	17	Invalid
Row-level permission control	18	Advanced edition
Transparent encryption	19	Advanced edition
Private table	20	Advanced edition

Example

• Start MogDB.

  gs_om -t start
  Starting cluster.
  ======================================================================
  .
  ======================================================================
  
  Successfully started .

• Stop MogDB.

  gs_om -t stop
  Stopping cluster.
  =========================================
  Successfully stopped cluster.
  =========================================
  End stop cluster.

• View MogDB status details, including instance status.

  gs_om -t status --detail
  
  [   Cluster State   ]
  
  cluster_state   : Normal
  redistributing  : No
  current_az      : AZ_ALL
  
  [  Datanode State   ]
  
      node             node_ip         port      instance                            state
  --------------------------------------------------------------------------------------------------
  1  pekpopgsci00235  10.244.62.204    5432      6001 /opt/mogdb/cluster/data/dn1/   P Primary Normal
  2  pekpopgsci00238  10.244.61.81     5432      6002 /opt/mogdb/cluster/data/dn1/   S Standby Normal

• Run the following commands on MogDB to generate the configuration file:

  gs_om -t generateconf -X  /opt/software/mogdb/clusterconfig.xml  --distribute
  Generating static configuration files for all nodes.
  Creating temp directory to store static configuration files.
  Successfully created the temp directory.
  Generating static configuration files.
  Successfully generated static configuration files.
  Static configuration files for all nodes are saved in /opt/mogdb/Bigdata/gaussdb/wisequery/script/static_config_files.
  Distributing static configuration files to all nodes.
  Successfully distributed static configuration files.

  Open the generated configuration file directory. You can see three new files.

  cd /opt/mogdb/Bigdata/gaussdb/wisequery/script/static_config_files
  ll
  total 456
  -rwxr-xr-x 1 omm dbgrp 155648 2016-07-13 15:51 cluster_static_config_plat1
  -rwxr-xr-x 1 omm dbgrp 155648 2016-07-13 15:51 cluster_static_config_plat2
  -rwxr-xr-x 1 omm dbgrp 155648 2016-07-13 15:51 cluster_static_config_plat3

• Roll back SSL certificates.

  gs_om -t cert --rollback
  [plat1] SSL cert files rollback successfully.
  [plat2] SSL cert files rollback successfully.
  [plat3] SSL cert files rollback successfully.