Troubleshooting Instances

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This topic provides basic instructions for app developers troubleshooting Redis On-Demand for Pivotal Cloud Foundry (PCF).

Debugging Using the CF CLI

To debug using the Cloud Foundry Command Line Interface (cf CLI) tool, see the commands below:

Temporary Outages

Redis for PCF service instances can become temporarily inaccessible during upgrades and VM or network failures.

Techniques for Troubleshooting Errors

You might see an error when using the Cloud Foundry Command-Line Interface (cf CLI) to perform basic operations on a Redis for PCF service instance:

• cf create
• cf update
• cf bind
• cf unbind
• cf delete

Parse a Cloud Foundry (CF) Error Message

Failed operations (create, update, bind, unbind, delete) result in 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 Pivotal Support when filing a ticket.

The task-id field maps to the BOSH task ID. For more information on a failed BOSH task, use the bosh task TASK-ID.

The broker-request-guid maps to the portion of the On-Demand 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.

Retrieve Service Instance Information

1. Log into the space containing the instance or failed instance.

   $ cf login
   

2. If you do not know the name of the service instance, run cf services to see a listing of all service instances in the space. The service instances are listed in the name column.

   $ 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      cache-small                  create succeeded
   

3. Run cf service SERVICE-INSTANCE-NAME to retrieve more information about a specific instance.

4. Run cf service SERVICE-INSTANCE-NAME --guid to retrieve the GUID of the instance, which is useful for debugging.

5. Redis for PCF v1.14 and later: Run cf tail SERVICE-INSTANCE-NAME/APP-NAME to retrieve the service instance of the app logs if the Log Cache CLI plugin is enabled. See Log Cache CLI plugin.

Retrieve the Password for a Redis Service Instance

If you want to access the Redis server for troubleshooting, you can find a Redis service instance password by creating a new service key.

Note: Pivotal recommends that you use this key for troubleshooting only, and that you delete the key after troubleshooting by using the command cf delete-service-key SERVICE-INSTANCE KEY-NAME.

If you encounter:

error: failed to set credentials in credential store:
The request includes an unrecognized parameter 'mode'.
Please update or remove this parameter and retry your request.

after upgrading from Redis for Pivotal Platform 2.3 to 2.4, it is likely because one or more installed on-demand brokers were not restarted during the upgrade. To clear the cached server version and enable your on-demand brokers to communicate with CredHub v2, do the procedure in Run BOSH Restart on Your On-Demand Service Brokers.

Error Messages from the Redis Client

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.

This section helps to troubleshoot the following errors:

• Maximum Number of Clients Reached
• Maxmemory Limit Reached
• Error When Running the Save Command

Maximum Number of Clients Reached

Symptom

You receive the following error:

-ERR max number of clients reached

Explanation

This is usually caused by apps opening multiple client connections to Redis.

Solution

Share or pool Redis connections within an app. Redis for PCF 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'.

Explanation

This occurs when the Redis server has reached its maxmemory limit.

Solution

Consider changing your maxmemory-policy. You can update this using the cf update-service parameters. For how to do this, see Customize an On-Demand Service Instance.

Error When Running the Save Command

Symptom

You receive the following error message when running redis-cli SAVE or issuing the save command using another Redis client:

-ERR

Explanation

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 redis-cli COMMAND or issuing a command using another Redis client:

-ERR unknown command

Explanation

For security reasons, certain commands such as CONFIG, SAVE, and BGSAVE are not available by default.

Solution

Talk to your operator about the availability of the command.

Apps Fail to Connect to the Service Instance

Symptom

Apps fail to connect to the Redis service instance.

Explanation

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 BOSH HotSwaps. 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:

1. Unbind the app:

   cf unbind-service APP-NAME SERVICE-INSTANCE-NAME
   

2. Rebind the app:

   cf bind-service APP-NAME SERVICE-INSTANCE-NAME
   

3. Restage the app:

   cf restage APP-NAME
   

Knowledge Base (Community)

Find the answer to your question and browse product discussions and solutions by searching the Pivotal Knowledge Base.

File a Support Ticket

You can file a support ticket here. Be sure to provide the error message from cf service YOUR-SERVICE-INSTANCE.

To expedite troubleshooting, if possible, provide your service broker logs, service instance logs, and BOSH task output. Your cloud operator should be able to obtain these from your error message.