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Josua Schmid
Josua Schmid

Posted on

8KB limit of Postgres NOTIFY

You can setup Rails ActionCable to use Postgres instead of Redis by adjusting the adapter configuration:

# config/cable.yml

  adapter: postgresql
  url: <%= ENV["DATABASE_URL"] %>
  channel_prefix: myapp_production
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This uses the Postgres LISTEN and NOTIFY commands.

As of writing, the NOTIFY payload is limited to 8000 bytes per default. If you're using Hotwire this may not always be enough and you will see error messages like this

PG::InvalidParameterValue (ERROR:  payload string too long)
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The solutions available to you are the following:

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