Metrics gathering

Adding and testing the vlogger sidecar

Vertica provides the vlogger image that sends logs from vertica.log to standard output on the host node for log aggregation.

To add the sidecar to the CR, add an element to the spec.sidecars definition:

spec:
  ...
  sidecars:
    - name: vlogger
      image: vertica/vertica-logger:1.0.0

To test the sidecar, run the following command and verify that it returns logs:

$ kubectl logs pod-name -c vlogger

2021-12-08 14:39:08.538 DistCall Dispatch:0x7f3599ffd700-c000000000997e [Txn
2021-12-08 14:40:48.923 INFO New log
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO> Log /data/verticadb/v_verticadb_node0002_catalog/vertica.log opened; #1
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO> Processing command line: /opt/vertica/bin/vertica -D /data/verticadb/v_verticadb_node0002_catalog -C verticadb -n v_verticadb_node0002 -h 10.20.30.40 -p 5433 -P 4803 -Y ipv4
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO> Starting up Vertica Analytic Database v11.0.2-20211201
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO>
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO> vertica(v11.0.2) built by @re-docker5 from master@a44ffabdf3f05e8d104426506b088192f741c485 on 'Wed Dec  1 06:10:34 2021' $BuildId$
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO> CPU architecture: x86_64
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO> 64-bit Optimized Build
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO> Compiler Version: 7.3.1 20180303 (Red Hat 7.3.1-5)
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO> LD_LIBRARY_PATH=/opt/vertica/lib
2021-12-08 14:40:48.923 Main Thread:0x7fbbe2cf6280 [Init] <INFO> LD_PRELOAD=
2021-12-08 14:40:48.925 Main Thread:0x7fbbe2cf6280 <LOG> @v_verticadb_node0002: 00000/5081: Total swap memory used: 0
2021-12-08 14:40:48.925 Main Thread:0x7fbbe2cf6280 <LOG> @v_verticadb_node0002: 00000/4435: Process size resident set: 28651520
2021-12-08 14:40:48.925 Main Thread:0x7fbbe2cf6280 <LOG> @v_verticadb_node0002: 00000/5075: Total Memory free + cache: 59455180800
2021-12-08 14:40:48.925 Main Thread:0x7fbbe2cf6280 [Txn] <INFO> Looking for catalog at: /data/verticadb/v_verticadb_node0002_catalog/Catalog
...

Generating core files

In some circumstances, you might need to examine a core file that contains information about the Vertica server container process.

Vertica server container process

The following steps generate a core file for the Vertica server process:

Use the securityContext value to set the privileged property to true:

apiVersion: vertica.com/v1
kind: VerticaDB
...
spec:
  ...
  securityContext:
    privileged: true

On the host machine, verify that /proc/sys/kernel/core_pattern is set to core:
```
$ cat /proc/sys/kernel/core_pattern
core
```
The /proc/sys/kernel/core_pattern file is not namespaced, so setting this value affects all containers running on that host.

When Vertica generates a core, the machine writes a message to vertica.log that indicates where you can locate the core file.

OpenShift core files

If you want to generate a core file in OpenShift, you must add the SYS_PTRACE capability in the CR to collect vstacks:

Use the securityContext value to set the capabilities.add property to ["SYS_PRTRACE"]:

    apiVersion: vertica.com/v1
 kind: VerticaDB
 ...
 spec:
   ...
   securityContext:
     capabilities:
       add: ["SYS_PTRACE"]

Apply the changes:

$ kubectl apply -f core-file-manifest.yaml

Get a shell in the container and execute vstack as the superuser:

$ kubectl exec svc/subcluster-name -- sh -c "echo root | su root /opt/vertica/bin/vstack"