Fix indexing for Polkadot dictionary

If your Polkadot snapshot is not v1.0, if may got the following error when start indexing the project:

ERROR failed to sync poi to mmr Error: Missing node in db

Now you can following these steps to fix the indexing issue.

1. Upgrade coordinator service

Update the version of coordinator service in docker-compose.yml change the version to v1.0.4. Then run the follow cmd to upgrade the container:

docker-compose up -d --no-deps coordinator

2. Start indexing Polkadot dictionary

Before start indexing polkadot dictionary, please make sure the polkadot project has been fully restored.

For indexing Polkadot dictionary, except the require fields, please enable purge POI on the panel to start indexing:

purge POI action will take a couple minutes to be completed. You can leave the page there or go to Networkservice log to check the details of progress:

Once the project start indexing, you may need a couple hours to get fully synced:

Please remember to disable the purge POI option when you try to restart indexing the project next time. Don’t apply this option to other projects.


I did all of the above, have selected purge DB option when started indexing, but I still see ‘ERROR failed to sync poi to mmr Error: Missing node in db’. And I see this in the Network section. My query_container doesn’t want to start.

what could be the problem?

my Polkadot database was fully restored (“finished main parallel loop”), but I have found this thing in the middle of my ‘restore.log’. I don’t know if this could be the cause of the problem, maybe it’s just a log display bug. at least there are no error messages in the log.

(sorry for two messages in a row, forum settings don’t allow me to post two pictures in one post.)

May I confirm where you put the polkadot .mmr file, you should expect that it is located at ${mmrPath}/poi/QmZ..../.mmr.

${mmrPath} is the path you config mmrPath in coordinator container

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Thank you for the answer. It looks like I didn’t copy .mmr before the restoring. Now everything is ok.

UPD: as a result, the indexer broke down and no longer starts. I deleted everything and started restoring from scratch

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