Logs not visible on UI how to fix this

Question

Anna Geller · Answer

Are you on Prefect Cloud Normally you should be able to refresh your browser page and see the logs then

Muddassir Shaikh · Answer

No hosted on personal server

Anna Geller · Answer

hmm could it be there is some issue with your Postgres instance running out of storage and not being able to store logs checking logs could be informative

Muddassir Shaikh · Answer

do you know the path where this logs are stored

Kevin Kho · Answer

It s a `logs` table in the postgresdb

Anna Geller · Answer

< Muddassir Shaikh> what I meant that checking the Server logs would be useful to see If you see any error messages such as no space left on Disk couldn t insert flow run logs to the DB

Muddassir Shaikh · Answer

while setting up prefect i didnt specify any database and installation was done automatic can you guide me with the path of the postgresdb which it uses

Kevin Kho · Answer

If you do `prefect server start` it uses Docker compose to spin up multiple containers There will be a postgres container which contains your Flows and metadata and logs

Prateek Saigal · Answer

< Kevin Kho> < Anna Geller> We don t see any server errors postgres errors on the prefect server on the docker logs Also do note that we are experiencing this for one of the agents rest agents are fine so don t think it will be a space issue What else could be the reason for this

Prateek Saigal · Answer

Also what set of username password and database we should use if we have to connect to the postgresql

Kevin Kho · Answer

If you use prefect server start it s <https github com PrefectHQ server blob master src prefect server config toml L36 L37|here>

Prateek Saigal · Answer

okay can connect to the database and can see the log table but don t see any logs from only one agent

Kevin Kho · Answer

You mean from the flows run on the agent Or are you expecting agent logs to show up

Prateek Saigal · Answer

I am expecting the logs of the flow runs on the agent

Anna Geller · Answer

To see flow run logs on the agent you need to start your agent with a flag show flow logs ```prefect agent local start show flow logs```

Muddassir Shaikh · Answer

< Anna Geller> i added showflow log flag still the logs are not visible on the UI below is my agent startup command ```prefect agent local start l my agent name n my agent name a port p home code utils show flow logs```

Anna Geller · Answer

can you show the flow code of the flow that doesn t generate logs properly

Anna Geller · Answer

if you use print you need to add log stdout=True to the task decorator and to log from tasks you need to use logger from the context ``` task def do sth logger = prefect context get logger <http logger info|logger info> some msg ```

Anna Geller · Answer

logging within flows is not supported in Prefect 1 0

Muddassir Shaikh · Answer

naah there is no issue in code as when i run the same code from different agent logs are shown on UI But i do see differences in prefect version of those agents

Muddassir Shaikh · Answer

This is fixed now The issue was with prefect version The prefect server had prefect version = 0 15 11 and this new agent had version=1 1 0 I downgraded it to 0 15 11 and now logs are visible on UI Thanks < Anna Geller> < Kevin Kho> < Prateek Saigal> for your time smile

Anna Geller · Answer

Great work finding and fixing the issue clap