PgBouncer K8s How-to - Enable Tracing

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Note: All commands are written for juju >= v3.1

If you’re using juju 2.9, check the juju 3.0 Release Notes.

Enable tracing

This guide contains the steps to enable tracing with Grafana Tempo for your PgBouncer K8s application.

To summarize:

Warning: This is feature is in development. It is not recommended for production environments.

This feature is available for Charmed PgBouncer K8s revision 162+ only.

Prerequisites

Enabling tracing with Tempo requires that you:

Deploy Tempo

First, switch to the Kubernetes controller where the COS model is deployed:

juju switch <k8s_controller_name>:<cos_model_name>

Then, deploy the dependencies of Tempo by following this tutorial. In particular, we would want to:

  • Deploy the minio charm
  • Deploy the s3 integrator charm
  • Add a bucket in minio using a python script
  • Configure s3 integrator with the minio credentials

Finally, deploy and integrate with Tempo HA in a monolithic setup.

Offer interfaces

Next, offer interfaces for cross-model integrations from the model where Charmed PgBouncer K8s is deployed.

To offer the Tempo integration, run

juju offer <tempo_coordinator_k8s_application_name>:tracing

Then, switch to the Charmed PgBouncer K8s model, find the offers, and integrate (relate) with them:

juju switch <k8s_controller_name>:<pgbouncer_k8s_model_name>

juju find-offers <k8s_controller_name>:

:exclamation: Do not miss the “:” in the command above.

Below is a sample output where k8s is the K8s controller name and cos is the model where cos-lite and tempo-k8s are deployed:

Store  URL                            Access  Interfaces
k8s    admin/cos.tempo                admin   tracing:tracing

Next, consume this offer so that it is reachable from the current model:

juju consume k8s:admin/cos.tempo

Consume interfaces

Relate Charmed PgBouncer K8s with the above consumed interface:

First, deploy Grafana Agent K8s from the latest/edge channel:

juju deploy grafana-agent-k8s --channel latest/edge

Then, integrate Grafana Agent K8s with the consumed interface from the previous section:

juju integrate grafana-agent-k8s:tracing tempo:tracing

Finally, integrate Charmed PgBouncer K8s with Grafana Agent K8s:

juju integrate pgbouncer-k8s:tracing grafana-agent-k8s:tracing-provider

Wait until the model settles. The following is an example of the juju status --relations on the Charmed PgBouncer K8s model:

Model     Controller  Cloud/Region        Version  SLA          Timestamp
database  k8s        microk8s/localhost   3.5.4    unsupported  18:12:15Z

SAAS   Status  Store       URL
tempo  active  k8s         admin/cos.tempo

App                  Version  Status  Scale  Charm                Channel        Rev  Address         Exposed  Message
grafana-agent-k8s    0.40.4   active      1  grafana-agent-k8s    latest/edge     93  10.152.183.52   no       grafana-dashboards-provider: off, logging-consumer: off, send-remote-write: off
pgbouncer-k8s        1.21.0   active      1  pgbouncer-k8s                         0  10.152.183.202  no       
postgresql-k8s       14.13    active      1  postgresql-k8s       14/edge        410  10.152.183.168  no       
postgresql-test-app           active      1  postgresql-test-app  latest/stable  211  10.152.183.174  no       received database credentials of the first database

Unit                    Workload  Agent  Address       Ports  Message
grafana-agent-k8s/0*    active    idle   10.1.241.205         grafana-dashboards-provider: off, logging-consumer: off, send-remote-write: off
pgbouncer-k8s/0*        active    idle   10.1.241.202         
postgresql-k8s/0*       active    idle   10.1.241.204         Primary
postgresql-test-app/0*  active    idle   10.1.241.203         received database credentials of the first database

Integration provider                       Requirer                                   Interface              Type     Message
grafana-agent-k8s:peers                    grafana-agent-k8s:peers                    grafana_agent_replica  peer     
grafana-agent-k8s:tracing-provider         pgbouncer-k8s:tracing                      tracing                regular  
pgbouncer-k8s:database                     postgresql-test-app:database               postgresql_client      regular  
pgbouncer-k8s:pgb-peers                    pgbouncer-k8s:pgb-peers                    pgb_peers              peer     
pgbouncer-k8s:upgrade                      pgbouncer-k8s:upgrade                      upgrade                peer     
postgresql-k8s:database                    pgbouncer-k8s:backend-database             postgresql_client      regular  
postgresql-k8s:database-peers              postgresql-k8s:database-peers              postgresql_peers       peer     
postgresql-k8s:restart                     postgresql-k8s:restart                     rolling_op             peer     
postgresql-k8s:upgrade                     postgresql-k8s:upgrade                     upgrade                peer     
postgresql-test-app:postgresql-test-peers  postgresql-test-app:postgresql-test-peers  postgresql-test-peers  peer     
tempo:tracing                              grafana-agent-k8s:tracing                  tracing                regular

Note: All traces are exported to Tempo using HTTP. Support for sending traces via HTTPS is an upcoming feature.

View traces

After this is complete, the Tempo traces will be accessible from Grafana under the Explore section with tempo-k8s as the data source. You will be able to select pgbouncer-k8s as the Service Name under the Search tab to view traces belonging to Charmed PgBouncer K8s.

Below is a screenshot demonstrating a Charmed PgBouncer K8s trace:

Example PgBouncer K8s trace with Grafana Tempo
Example PgBouncer K8s trace with Grafana Tempo3830×2116 776 KB

Feel free to read through the Tempo HA documentation at your leisure to explore its deployment and its integrations.

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