SEMP can be used by applications to gather statistics from an event broker. Almost every CLI command issued to an event broker has a corresponding SEMP counterpart, and these can be used to build simple applications, even over the command line.
Example Command to Gather Statistics
The example command show below can be run on a UNIX system to get the Message VPN stats connected to an event broker:
curl http://192.168.1.2:80/SEMP -u admin:admin -d "<rpc semp-version='soltr/5_5'> <show> <message-vpn> <vpn-name>test_vpn</vpn-name> <stats/> </message-vpn> </show> </rpc>"
You need to ensure that the event broker’s management URL and VPN name are replaced with the corresponding values. XPath can be used to filter the output of the command to extract certain values, such as the total ingress discards on a VPN.
Using this facility, third party monitoring frameworks such as Nagios can be integrated with Solace PubSub+.
In addition to the above, it's possible to use the Solace API to send and receive SEMP requests to monitor an event broker. For more information on sending SEMP requests over the message bus, refer to the sample application SempGetOverMB.java or sempGetOverMb.c, available in the JCSMP and C SDKs. The examples demonstrate how a SEMP request/response can be accomplished over the message bus.
Important Statistics
Shown below are some important event broker statistics which can be gathered using SEMP. This is not a comprehensive list; for more information refer to the Solace CLI reference. These are intended to serve as a starting point for event broker monitoring using SEMP, and you should monitor additional statistics using SEMP as required by your applications' use-cases.
System Level Statistics
| System Level Stats CLI Command | Description |
|---|---|
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Returns details of the current SolOS version running on the appliance |
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Returns details of hardware on the Solace appliance such as power supplies, HBA link status and LUN details, etc. |
show disk
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Returns details of the disks on the appliance as well as the RAID's redundancy state |
show redundancy
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Returns the state of appliance redundancy and links to the mate ADB |
show message-spool detail
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Returns the state of the message-spool as well as appliance level details of endpoints, ingress and egress flows, transactions, etc |
show message-spool rates
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Returns the ingress and egress message rates for guaranteed messaging for each message-vpn |
show stats client
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Returns the total number of clients connected to an appliance |
show replication statistics
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Returns details of number of messages queued to the replication mate as well as those which have been received when on standby |
show config-sync database
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Returns the state of the config-sync database for all message-vpns |
Message VPN Level Statistics
| Message VPN Level Stats CLI Command | Description |
|---|---|
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Returns message-vpn level statistics such as number of ingress and egress discards, active connections and subscriptions, and ingress & egress message rates. The active connections and subscriptions can be used as indicator of the current capacity of a message-vpn. |
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Returns ingress and egress discard statistics and transaction processing statistics for a given message-vpn |
show message-spool message-vpn <vpn-name> rates
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Returns the ingress and egress, message rates for each endpoint in the message-vpn |
show config-sync database message-vpn <vpn-name> detail
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Returns the details of the config-sync database for a message vpn such as ownership details and sync state |
show message-vpn <vpn-name> replication detail
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Returns the replication state for a message-vpn including the state of the replication bridge and replication queue. |
Client Level Statistics
| Client Level Stats CLI Command | Description |
|---|---|
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Returns important client details as well as ingress and egress statistics |
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Returns TCP level details on the connection, such as retransmits, as well as send and receive queue details |
show client <name> stats queues [detail]
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Returns details of a client as well as the state of its egress buffers |
show client <name> slow-subscriber
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Returns the list of clients which have been marked as slow subscribers by the appliance |
Queue Level Statistics
| Queue Level Stats CLI Command | Description |
|---|---|
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Returns queue details such as bind count, current spool usage, etc |
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Returns queue details as well as topic subscriptions added to it and its creator |
show queue <name> stats
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Returns statistics such as number of messages spooled, high water mark, flow ID, number of messages deleted and expired as well as client bind statistics |
Bridge Level Statistics
| Bridge Level Stats CLI Command | Description |
|---|---|
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Returns bridge level statistics such as bridge connection state and uptime, remote message-vpn state, etc |
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Returns statistics of total messages sent and received long with ingress and egress message rates |
PubSub+ Cache Level Statistics
| SolCche Level Stats CLI Command | Description |
|---|---|
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Returns the administrative and operational status of a PubSub+ Cache instance, as well as configuration details. |
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Returns details of cached data such as number of messages and topics cached, as well as current incoming and outgoing data message rates, and number of messages discarded. |
show cache-instance <name> message-vpn <vpn-name> remote topics
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Returns details of topic subscriptions on which the cache-instance contains data, as well as the number of current and cumulative messages for each topic. |
show cache-cluster <name> message-vpn <vpn-name> detail
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Returns configuration details of the cache-cluster such as max-memory and max-topics as well as event thresholds |
show distributed-cache <name> message-vpn <name> detail
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Returns details of the distributed cache configuration such as scheduled-delete and heartbeat-timeout. |