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Logger

A Logger interface is injected into the handler context with ctx.log. It is bound to the namespace sqd:processor:mapping. The context logger is a recommended way of logging for squid processors. Logger exposes the following logging levels, in order of increasing severity:
  • TRACE
  • DEBUG
  • INFO
  • WARN
  • ERROR
  • FATAL
By default, the logging level is set to INFO. And here is an example: 
processor.run(new TypeormDatabase(), async (ctx) => {
  ctx.log.trace("Trace Log example");
  ctx.log.debug("Debug Log example");
  ctx.log.info("Info Log example");
  ctx.log.warn("Warn Log example");
  ctx.log.error("Error Log example");
  ctx.log.fatal("Fatal Log example");
});

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Overriding the log level

The log level can be overridden by setting a matching namespace selector to one of the SQD_TRACE, …, SQD_FATAL env variables. In particular, to set the handler logs level to DEBUG set the environment variable SQD_DEBUG to sqd:processor:mapping: 
SQD_DEBUG=sqd:processor:mapping
The namespace selector supports wildcards, so one can also enable internal debug logs of @subsquid/evm-processor with 
SQD_DEBUG=sqd:processor*
since all processor context loggers inherit the processor-level namespace sqd:processor.

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Accessing logs of a deployed Squid

Processor logs can be inspected once the squid is deployed to Cloud: 
sqd logs -n <name> -s <slot> -f --level=<level>
or 
sqd logs -n <name> -t <tag> -f --level=<level>
The available levels are:
  • info
  • warning
  • debug
  • error - will fetch messages emitted by
    • ctx.log.error
    • ctx.log.fatal
    • ctx.log.trace
See CLI Reference or sqd logs --help for a full list of log options supported by SQD Cloud.