upgrade arango 3.8 -> 3.9 produces "decoding error" (actually started with another issue)

[akomm]

I started with arangojs 8.6.* and anraogdb:3.8 (docker)

upgraded anraogdb:3.8 to 3.9.
Run upgrade via "docker-compose run arangodb --database.auto-upgrade" successfuly.
Logged in to verify using arangodb web interface. Data was there, version was shown 3.9.x (don't recall last number but most recent).

Get on any interaction with server via arangojs "decoding error" with no other useful info. I debugged and figured out the erronumber returned from arangodb server is 10

There was no specific info what parameter was unexpected or wrong. I've assumed maybe I need to upgrade the js adapter because it tries to send a request that is not correct for the newer arangodb version.

Upgraded arangojs to 9.*

Error ist the same.

Upgraded arangojs to 10.*

Error is the same.

When I debug and check the error response from arangodb, There is zero information from arangodb that gives any hint as to what exactly is incorrect. Its just a 400 Bad request with payload:

{
    "error": true,
    "errorNum": 10,
    "errorMessage": 'decoding error',
    "code": 400
  }

I upgraded arangodb:3.9 further to arangodb:3.10 similarly to the above upgrade from 3.8 to 3.9. Confirmed data still readable and present, confirmed the version in web interface changed to 3.10.

Same errors.

I upgraded arangodb:3.10 to arangodb:3.11, same checks, all green.

Error changed to "501 not implemented" with payload:

{
    "error": true,
    "errorNum": 9,
    "errorMessage": 'Parsing for transfer-encoding of type chunked not implemented.',
    "code": 501
  }

The actual reason why I have started upgrading is that I had another issue with inconsistent results, where a query via the client returned a different data, than running the literally same query and params on arango web interface - I literally have copy & pasted the query from the aql instance, including the bindVars and pasted t he query and values into the interface.

Since I already had an issue in another app with the same version, where the arangodb server would crash under certain filter conditions and an upgrade fixed it, I've decided to make an upgrade on another app with the above inconsistent result issue too.

[akomm]

Interestingly, after reaching arangodb:3.11 and downgrading arangojs to 8.* the errors are gone... (9.* still same errors)

But the initial issue of different results on exactly the same query and parameters between web interface and arangojs is present :(.

Since the result on web interface is correct and the one returned by Database.query is missing items in a nested array, the issue must be on the client side. And I've just returned to the initial version I had anyway...

[akomm]

I think I had found the source of "decoding error" and its ridiculous. Its not error on the request from client itself, its an issue with a format passed to a date_ function. But only when I bind it as a variable in the aql-template string. Passing it as a literal string works.