Redis span ops marked as 'db' instead of 'cache'

[rahul-kumar-saini]

Redis span ops marked as 'db' instead of 'cache'

[s1gr1d]

Hello, thanks for writing! We are indeed working on a feature which let's you define specific prefixes for your cache keys. The API will possibly look something like this: integrations: [Sentry.redisIntegration({ cachePrefixes: ['cache:'] })].

If the key is prefixed with one of the defined prefixes, the ops will be marked as cache.[..].

[rahul-kumar-saini]

Hi @s1gr1d! Is there any way for me to also only have certain commands instrumented? Eg let's say I only care for get/set/delete and don't care for other Redis commands?

[s1gr1d]

Currently, there isn't. Would you want to specify certain Redis commands to be instrumented in general or just when you're using Redis as a cache? Meaning, Redis would be instrumented for all commands but only when a key is prefixed with e.g. cache: we would drop commands which are not specified.

[s1gr1d]

If you want, you can already try adding cache prefixes to the integration with the latest version of Sentry. Currently they pick up get and set.

[rahul-kumar-saini]

Would you want to specify certain Redis commands to be instrumented in general or just when you're using Redis as a cache?

We use Redis for a couple different things, eg sometimes we use EVAL to run a script. Let's say I'm only interested in gets/sets/deletes in general across Redis, is that something I can currently do using the cache prefixes?

Meaning, Redis would be instrumented for all commands but only when a key is prefixed with e.g. cache: we would drop commands which are not specified.

I'm not sure what this means - if I set { cachePrefixes: ['cache.'] } I assume a get span will have op cache.get, but what would something like PUBLISH or EVALSHA have? cache.publish and cache.evalsha? Or would those be dropped?

Since cachePrefixes is a list of strings, what would having multiple strings there do? Eg what is the expected behavior of setting { cachePrefixes: ['cache.', 'redis.'] }?

[mydea]

So cachePrefixes defines a list of prefixes, if any of them is matched we will ensure these spans will show up as cache spans in the UI. So e.g. { cachePrefixes: ['cache.', 'redis.'] } means that e.g. these: cache.publish or redis.publish will be shown as cache spans, but other.publish will not. Does this make sense?

[rahul-kumar-saini]

So cachePrefixes defines a list of prefixes, if any of them is matched we will ensure these spans will show up as cache spans in the UI. So e.g. { cachePrefixes: ['cache.', 'redis.'] } means that e.g. these: cache.publish or redis.publish will be shown as cache spans, but other.publish will not. Does this make sense?

I see, so what this sounds like to me is that anything I specify as cache.something will show up in the Caches performance UI if I have "cache" in my cachePrefixes. Going back to my original issue however, the Redis integration (as of SDK 8.2.1 at least) marks ioredis commands as db.<command> instead of redis.<command> or cache.<command>.

So even if I set cache prefixes, it probably won't resolve that issue?

[rahul-kumar-saini]

It looks like the docs on cache prefixes are describing an entirely different usage. The docs are saying the cache prefixes array is used for filtering what the cache key itself is prefixed by, rather than the span op of the cache span?

[lforst]

@rahul-kumar-saini So in general the docs you are referring to are our "develop" docs which are not really intended for end-user consumption but rather for SDK maintainers, so take everything in there with a grain of salt because it is often idealistic and the reality looks different.

The docs are saying the cache prefixes array is used for filtering what the cache key itself is prefixed by, rather than the span op of the cache span?

The docs here say that if you have a cache invocation, and the cache key matches one of the prefixes, its db span should be wrapped in a cache span. In reality, what this will mean for the JS SDK is that the cache span will be wrapped by the db span due to a technical limitation. If the cache key doesn't match any of the prefixes, a cache span will not be created, the db span will stay. This is so that you aren't getting random redis spans in your caches view when you don't use redis as a cache. All redis operations will however still likely show up in the queries view.

The caches view will launch soon and we are just in the process of building redis integrations. They are still very much experimental.

cc @AbhiPrasad because he is looking at this soon

[s1gr1d]

We have two variants, that will be supported with the upcoming release. Each one instruments a set of redis commands.

• cache.get: get, mget
• cache.put: set, setex

All other commands will be handled as db spans. In regards to your question about other commands like evalsha: Do you use any other commands to interact with your cache (which ones)?

Currently, it is not possible to evaluate other commands than listed above as cache spans.