Disappearing data

[qbazd]

Hi all.

I've been playing with this module mainly for stats with Grafana.
I'm getting some strange behaviour.
As data come, reading older data is being unavailable.

My test environment is Redis 5.0.3 (compiled from source).

My test case is to write timeseries of values (time is 0 to sample_len with values of time).
After writing time series. Read whole as smaller overlapping chunks.

I'm expecting to read same chunk size (except for the end of course).
With the first value as beginning of chunk.

I've simplified test to below python source:

import redis

sample_len = 1024
chunk_size = 4
read_chunk_size = 10
shift = 0

REDIS_POOL = redis.ConnectionPool(host='127.0.0.1', port=10302)
redis_client = redis.Redis(connection_pool=REDIS_POOL)

redis_client.delete("test_key")

redis_client.execute_command("ts.create", 'test_key', 0, chunk_size)

for i in range(sample_len):
  redis_client.execute_command("ts.add", 'test_key', i , i)

for i in range(sample_len):
  s = i + shift 
  var = redis_client.execute_command(*['ts.range', 'test_key', s, s + read_chunk_size-1])

  if len(var) > 0:
    print([i, len(var), int(var[0][1])])
  else:
    print([i, 0, "should be " + str(i)])

The example output is:

[0, 4, 0]
[1, 0, 'should be 1']
[2, 0, 'should be 2']
[3, 0, 'should be 3']
[4, 4, 4]
[5, 0, 'should be 5']
[6, 0, 'should be 6']
[7, 0, 'should be 7']
[8, 4, 8]
[9, 0, 'should be 9']
[10, 0, 'should be 10']
[11, 0, 'should be 11']
...
[764, 4, 764]
[765, 0, 'should be 765']
[766, 0, 'should be 766']
[767, 0, 'should be 767']
[768, 10, 768]
[769, 10, 769]
[770, 10, 770]
[771, 10, 771]
[772, 10, 772]
...
[1014, 10, 1014]
[1015, 9, 1015]
[1016, 8, 1016]
[1017, 7, 1017]
[1018, 6, 1018]
[1019, 5, 1019]
[1020, 4, 1020]
[1021, 3, 1021]
[1022, 2, 1022]
[1023, 1, 1023]

I've done tests with branch "master".
Also tested "labels" branch as there was some issues solved, but no luck (diffrent output).

When I do same test in a single loop it works as expected.

What to you think of this?

Best regards.