ArangoSearch: Failed to retrieve document from view after updating it in collection

[mkv]

My Environment

• ArangoDB Version: 3.8.4
• Deployment Mode: Cluster
• Infrastructure: own
• Operating System: Linux

Steps to reproduce

1. Create collection
2. Create view:

   {
   "writebufferIdle": 64,
   "type": "arangosearch",
   "writebufferSizeMax": 33554432,
   "consolidationPolicy": {
   "type": "tier",
   "segmentsBytesFloor": 2097152,
   "segmentsBytesMax": 5368709120,
   "segmentsMax": 10,
   "segmentsMin": 1,
   "minScore": 0
   },
   "primarySort": [],
   "globallyUniqueId": "c35357188/",
   "id": "35357188",
   "storedValues": [],
   "writebufferActive": 0,
   "consolidationIntervalMsec": 1000,
   "cleanupIntervalStep": 2,
   "commitIntervalMsec": 1000,
   "links": {
   "entities": {
     "analyzers": [
       "norm_en",
       "identity"
     ],
     "fields": {
       "title": {}
     },
     "includeAllFields": false,
     "primarySortCompression": "lz4",
     "storeValues": "id",
     "trackListPositions": false
   }
   },
   "primarySortCompression": "lz4"
   }

   or

{
  "writebufferIdle": 64,
  "type": "arangosearch",
  "writebufferSizeMax": 33554432,
  "consolidationPolicy": {
    "type": "tier",
    "segmentsBytesFloor": 2097152,
    "segmentsBytesMax": 5368709120,
    "segmentsMax": 10,
    "segmentsMin": 1,
    "minScore": 0
  },
  "primarySort": [],
  "globallyUniqueId": "c18297111/",
  "id": "18297111",
  "storedValues": [],
  "writebufferActive": 0,
  "consolidationIntervalMsec": 1000,
  "cleanupIntervalStep": 2,
  "commitIntervalMsec": 1000,
  "links": {
    "entities": {
      "analyzers": [
        "norm_en",
        "identity"
      ],
      "fields": {},
      "includeAllFields": true,
      "primarySortCompression": "lz4",
      "storeValues": "id",
      "trackListPositions": false
    }
  },
  "primarySortCompression": "lz4"
}

4. Continuously run query to get document

   FOR v IN search_view SEARCH v._key == 'some_key' RETURN v._key

5. Update some field in a document in the collection. The field may be linked to the view or not.

   UPDATE { _key: 'some_key', some_field:'value1' } IN entities

Problem: After update we cannot receive document (looks like it is disappeared) from view for 2-3 seconds.

Expected result: Last version of the document is available all the time, independently of any updates.

[Delicious-Bacon]

I'm having this issue as well. I use importDocuments with onDuplicateUpdate option.

Here's the kind of results I get:

• All documents retrieved as null: [null,null,null],
• or partial results: [null,null,{"id":"225","t":"Item 225"}]

The expected result: [{"id":"348","t":"Item 348"}, {"id":"112","t":"Item 112"}, {"id":"225","t":"Item 225"}]

I run the latest 3.9.2 version.

I use Golang SDK and use ImportDocuments function with ImportOnDuplicateUpdate preference if SDK matters.

I grab document _keys in a subquery and then loop over the subquery _keys array to "JOIN" the results with another collection so this looks like the document first exists because the subquery finds the _key and then disappears when querying for it in the second query.

I can't rely on Arango giving partial or incorrect results during updates.

---

You mentioned that it

(looks like it is disappeared) from view for 2-3 seconds.

Yes, it looks like it does REPLACE where it would first DELETE the document and then INSERT a new copy instead of doing an UPDATE.

Note: while I thought this might have been an eventual consistency issue, it makes no sense, because in that case, the query would just return the old version of the document, not null.

[MBkkt]

answered here https://github.com/arangodb/arangodb/issues/17482

[MBkkt]

Fixed starting from 3.11