getAnyReplica queries throws DocumentUnretrievableError for non-existent keys

Node.js SDK
1

Hello,

I’m using “couchbase”: “^4.3.1” in my Node.js application. We use Couchbase as a caching mechanism (2 hours) for some data received from another endpoint.

I observed that once a document expires (or it doesn’t exist), when querying non-existent keys from the primary node, I receive DocumentNotFoundError as expected. However, based on the current code, we’re also querying the replicas 2 times (using getAnyReplica). For the same non-existent keys, I consistently receive DocumentUnretrievableError from the replicas.

No matter if I call the replica with a fresh key or an expired one, the response from getAnyReplica is the same error:

DocumentUnretrievableError: document unretrievable] {
  cause: [Error: document_irretrievable (102)] {
    ctxtype: 'key_value',
    code: 102,
    id: 'super-random-not-found-key',
    opaque: 20,
    cas: Cas<0>,
    status_code: 1,
    enhanced_error_info: undefined,
    retry_attempts: 0,
    retry_reasons: []
  },
  context: KeyValueErrorContext {
    status_code: 1,
    opaque: 20,
    cas: Cas<0>,
    key: undefined,
    bucket: undefined,
    collection: undefined,
    scope: undefined,
    context: '',
    ref: ''
  }
}

I want to modify the code a little bit to make it handle the responses more gracefully and I’m in a dilemma if doing something like this if (error instanceof DocumentNotFoundError || error instanceof DocumentUnretrievableError) { would be a correct approach.

Is throwing DocumentUnretrievableError expected? If not, how would you recommend I handle DocumentUnretrievableError?

Thank you!

2

Hi @tudor

Yes this is expected. A regular non-replica collection.get() call will fail with DocumentNotFoundError, while if a collection.getAnyReplica() call fails with any reason (including that a document wasn’t present), then DocumentUnretrievableError is raised.

1 Like
3

Thank you so much for the response!

Just to confirm, is there any scenario where the collection.getAnyReplica() call would respond with DocumentNotFoundError or is always the UnretrievableError?

4

It should always be the UnretrievableError.

2 Likes
5

Sorry to bother you, but could you provide me the documentation that covers this? I couldn’t find a specific place where this gets mentioned.

6

It’s here in the API doc -

And here in the rfc -

1 Like