This topic for app developers gives you basic instructions for troubleshooting on-demand Redis for VMware Tanzu Application Service service instances.
Start here if you are responding to a specific error or error messages.
The following errors occur in multiple services:
Apps fail to connect to the service instance |
|
---|---|
Symptom | Apps fail to connect to the Redis service instance. |
Cause | The Redis on-demand service broker now binds apps to service instances using BOSH DNS. Service bindings return the DNS address instead of the IP address. If an operator enables the BOSH HotSwaps feature, any apps with service bindings that do not use BOSH DNS will fail to connect to the Redis service instance. For more information, see Enable BOSH HotSwaps to Reduce Downtime. For more information about service bindings, see Service Bindings in the Cloud Foundry documentation. |
Solution | Convert service instance bindings to use BOSH DNS. To do so, unbind, rebind, and restage all apps that were bound to a service instance using an IP address as follows:
|
No Metrics from log cache |
|
---|---|
Symptom | You receive no metrics when running the cf tail command. |
Cause | Depending on your versions of TAS for VMs and Redis for Tanzu Application Service, this can occur when the Firehose is deactivated in the TAS for VMs tile. |
Solution | Ask your operator to ensure that the V2 Firehose checkbox is selected, and the Enable Log Cache syslog ingestion check box is cleared in the TAS for VMs tile. For more information about configuring these check boxes, see Enable Syslog Forwarding. |
The following errors are specific to Redis for Tanzu Application Service:
Certain errors are returned to the Redis client instead of being recorded in the logs. The Redis protocol represents errors as simple strings beginning with a -
character.
Maximum number of clients reached |
|
---|---|
Symptom | You receive the following error: -ERR max number of clients reached |
Cause | This is usually caused by apps opening multiple client connections to Redis. |
Solution | Share or pool Redis connections within an app. Redis for Tanzu Application Service configures Redis to accept 10000 client connections. This can be confirmed by running the INFO command using the Redis CLI. |
Maxmemory limit reached |
|
---|---|
Symptom | You receive the following error: -OOM command not allowed when used memory > 'maxmemory'. |
Cause | This occurs when the Redis server has reached its maxmemory limit. |
Solution | Consider changing your maxmemory-policy. You can update this using the |
Error when running the save command |
|
---|---|
Symptom | You receive the following error message when running -ERR |
Cause | This might occur when the Redis server's disk is full. |
Solution | A more informative message might be logged in the syslog. For more information, see Syslog Errors. |
Unknown command error |
|
---|---|
Symptom | You receive the following error message when running -ERR unknown command |
Cause | For security reasons, certain commands such as CONFIG , SAVE , BGSAVE and ACL are not available by default. |
Solution | Talk to your operator about the availability of the command. |
See the following sections for troubleshooting techniques when using the Cloud Foundry Command-Line Interface (cf CLI) to perform basic operations on a Redis for Tanzu Application Service service instance.
Basic cf CLI operations include create
, update
, bind
, unbind
, and delete
.
See the following table for Cloud Foundry Command Line Interface (cf CLI) commands commonly used while debugging:
To view the... | Command |
---|---|
API endpoint, org, and space | cf target |
Service offerings available in the targeted org and space | cf marketplace |
Apps deployed to the targeted org and space | cf apps |
Service instances deployed to the targeted org and space | cf services |
GUID for a specific service instance | cf service SERVICE-INSTANCE --guid |
Service instance or application logs | cf tail SERVICE-INSTANCE/APP |
Failed operations (create, update, bind, unbind, delete) cause an error message. You can retrieve the error message later by running the cf CLI command cf service INSTANCE-NAME
.
$ cf service myservice Service instance: myservice Service: super-db Bound apps: Tags: Plan: dedicated-vm Description: Dedicated Instance Documentation url: Dashboard: Last Operation Status: create failed Message: Instance provisioning failed: There was a problem completing your request. Please contact your operations team providing the following information: service: redis-acceptance, service-instance-guid: ae9e232c-0bd5-4684-af27-1b08b0c70089, broker-request-id: 63da3a35-24aa-4183-aec6-db8294506bac, task-id: 442, operation: create Started: 2017-03-13T10:16:55Z Updated: 2017-03-13T10:17:58Z
Use the information in the Message
field to debug further. Provide this information to Support when filing a ticket.
The task-id
field maps to the BOSH task ID. For more information about a failed BOSH task, use the bosh task TASK-ID
.
The broker-request-guid
maps to the portion of the On-Demand Service Broker log containing the failed step. Access the broker log through your syslog aggregator, or access BOSH logs for the broker by typing bosh logs broker 0
. If you have more than one broker instance, repeat this process for each instance.
To retrieve information about the service instance that you can use for debugging:
Log into the space containing the instance or failed instance.
$ cf login
If you do not know the name of the service instance, you can view a listing of all service instances in the space by running:
cf services
The service instances are listed in the name
column.
For example:
$ cf services
Getting services in org my-org / space my-space as user@example.com...
OK
name service plan bound apps last operation
my-instance p.redis on-demand-cache create succeeded
Retrieve more information about a specific service instance by running:
cf service SERVICE-INSTANCE-NAME
Retrieve the GUID of the service instance by running:
cf service SERVICE-INSTANCE-NAME --guid
This is useful for debugging.
If the Log Cache CLI plugin is enabled, you can retrieve logs for the service instance by running:
cf tail SERVICE-INSTANCE-NAME/APP-NAME
For more information, see Log Cache CLI plug-in.
If you want to access the Redis server for troubleshooting, you can find a Redis service instance password by creating a new service key.
VMware recommends that you use this key for troubleshooting only, and that you delete the key after troubleshooting by running the command cf delete-service-key SERVICE-INSTANCE KEY-NAME
.
For instructions on how to retrieve the password, see Retrieve the password for a Redis service instance.
Redis for Tanzu Application Service service instances can become temporarily inaccessible during upgrades and VM or network failures.
Find the answer to your question and navigate product discussions and solutions by searching Broadcom Support.
You can file a support ticket here. Include the error message from cf service YOUR-SERVICE-INSTANCE
.
To expedite troubleshooting, provide your service broker logs, service instance logs, and BOSH task output. Your cloud operator can obtain these from your error message.