Fiddle Production Manual

First make sure you are familiar with the design of fiddle by reading the DESIGN doc.

Alerts

Items below here should include target links from alerts.

fiddler_pods

Fiddle should run enough fiddler pods that the number of idle fiddle pods never gets too low. Check the amount of traffic that fiddle is receiving and if the traffic is legitimate then increase the number of replicas in the fiddler.yaml file.

NamedFiddlesFailing

Some of the named fiddles checked into the Skia repo have stopped compiling or running. To see what the compilation errors are and to help with fixes, it is probably easiest to reproduce locally using the following steps:

1. Check out Skia https://skia.org/docs/user/download/. All following steps should be executed from the Skia root.
2. Sync third party deps by executing python2 tools/git-sync-deps
3. Set up a debug GN build target bin/gn gen out/Debug
4. Re-create the all_examples.cpp python tools/fiddle/make_all_examples_cpp.py
5. Build the fiddle_examples ninja -C out/Debug fiddle_examples

Once the fixes have been committed to the Skia repo, they should be synced into fiddle and the errors should go away.

For runtime errors, it is best to look at the logs of the named-fiddles pod.

Another way to mitigate the alert is to disable the example by putting #ifdef 0 as the first line and #endif as the last line, then committing.

Key metrics: named_fiddles_errors_in_examples_run

InvalidNamedFiddles

Some of the named fiddles cannot be parsed (using //named-fiddles/go/parse). This might mean that there is a typo in the macro, or a new macro has been introduced and the parsing code needs updating.

For more information, look at the logs of the named-fiddles pod.

Key metrics: named_fiddles_examples_total_invalid