Error Workflow triggered with 'seems to be' successful completed workflows

[Romuald_BARON]

Hi all,

I’m creating this question following this thread which seems to be similar to my issue:

Cron job workflows connecting to postgresql are failing at random intervals

We have twenty cron jobs actively running at an interval of 5 to 9 mins each. We notice that these cron jobs fail at random intervals of a day. Sometimes it does not happen but sometimes it happens frequently. What is the best way to troubleshoot at which point of the workflow we receive the error? Workflow setup is simple → Cron configured for every 5 minutes → postgreSQL node runs one delete Query and one insert query. It does not throw any specific error message for now, it simply mentions…

So, I got few error workflows being triggered but when I look at their execution, most of the time, they were completed successfully. They are either in Failed status with 0 node in error, or not showing being executed.

I had a look at logs from main & workers pods and I don’t see anything suspicious.
So I was thinking that maybe the issue could be linked to Redis.

Here is the redis configuration:

    maxmemory 3gb
    maxmemory-policy allkeys-lru 
    loglevel verbose

Here is REDIS related configuration:

  QUEUE_BULL_REDIS_HOST: n8n-redis-master
  QUEUE_BULL_REDIS_PORT: "6379"
  QUEUE_BULL_REDIS_DB: "0"
  QUEUE_BULL_REDIS_TIMEOUT_THRESHOLD: "30000"

And I’ve noticed that there are few blocked clients, not sure it’s related:

# Clients
connected_clients:22
cluster_connections:0
maxclients:10000
client_recent_max_input_buffer:20553
client_recent_max_output_buffer:0
blocked_clients:5
tracking_clients:0
clients_in_timeout_table:5

Do you think this could be linked?
Let me know what can be useful for investigating this issue.

Information on your n8n setup

• n8n version:0.228.2
• Database you’re using (default:PostgreSQL): PostgreSQL
• Running n8n with the execution process [own(default)]: default
• Running n8n via [npm]: k8s with 1 main (16GB/0.5->8CPU), 1 webhook (4GB/0.5->1CPU), 5-35 workers (8GB/0.5->8CPU), 1 redis (4GB/0.1->1CPU)