Invoking export-blocks leads to "essential task failed" error messages

[pepyakin]

When invoking export-block command there are error messages about "essential task failed". However, it does not seem to be an issue for exporting blocks since they do get exported. So it's just bad messaging.

./private/builds/7d8f00b90c/polkadot export-blocks -d /tmp/polkadot-7d8f00b90c-db private/blocks-386880
2022-01-04 16:58:22 Essential task `basic-block-import-worker` failed. Shutting down service.
2022-01-04 16:58:22 Essential task `transaction-pool-task-0` failed. Shutting down service.
2022-01-04 16:58:22 DB path: /tmp/polkadot-7d8f00b90c-db/chains/polkadot/db/full
2022-01-04 16:58:22 Essential task `txpool-background` failed. Shutting down service.
2022-01-04 16:58:22 Essential task `transaction-pool-task-1` failed. Shutting down service.

[bkchr]

Yeah I have seen similar things. This seems to be correlated with starting only half of the node and also dropping some stuff that isn't needed.

[dnjscksdn98]

Faced to the same issue when exporting blocks. Is there any updates on this issue?
But I do also think there's no problems to the exported block data. Just for the error message.

[ggwpez]

This also happens when benchmarking sets up a client.
It does not need the additional components, so shutting them down is fine.
Maybe the code could be changed to actually never start these components, but new_partial does it.

[abh-swar]

Hello, was someone able to resolve this issue?

CC: @bkchr

[nazar-pc]

I think a few things just need to be kept in memory rather than being dropped, but I didn't bother to dig into it yet as it is harmless.

[bkchr]

Yes, as I said above this is because we drop some things that we start as essential task. This will then lead to this log message. And yes, these messages are not problematic.

[viveksharmapoudel]

@bkchr In our case, there is failed error message and no block being exported....

root@localhost:~# sudo ./polkadot export-blocks --chain kusama --from 20 --to 4000 --base-path /chains_data
backup.kusama

2022-12-27 10:31:54 👶 Creating empty BABE epoch changes on what appears to be first startup.
2022-12-27 10:31:54 DB path: /chains_data/chains/ksmcc3/db/full
2022-12-27 10:31:54 Essential task txpool-background failed. Shutting down service.
2022-12-27 10:31:54 Exporting blocks from #20 to #4000

root@localhost:~# ls -l
-rw-r--r-- 1 root root 0 Dec 27 10:31 backup.kusama