`list_consumer_group_offsets` is always 10x slower that origin `kafka-consumer-groups.sh --describe`

[jdxin0]

list_consumer_group_offsets is always 10x slower that origin kafka-consumer-groups.sh --describe.

bin/kafka-consumer-groups.sh --bootstrap-server 127.0.0.1:9092 --describe --group test

admin_client = KafkaAdminClient(bootstrap_servers=["127.0.0.1:9092"])
admin_client.list_consumer_group_offsets('test')

kafka version 1.1
kafka-python version 1.4.6

[jeffwidman]

If you list multiple consumer groups, this may help: #1807

If you're just doing a single one, then keep in mind that IIRC, version 1.1 doesn't use the admin APIs but instead internal scala code and that may short-circuit some extra checks/code in the broker... I'm not sure.

I would normally expect the Java code to be slightly faster than Python, but not a huge amount for this trivial of thing.

Can you show timings to illustrate the 10x slowness?

[jdxin0]

I have almost ten kafka clusters to manage, it all seem the same.

Here is the performance of one 3-nodes cluster with version 1.1.
This cluster has 24 consumer_groups.

list_consumer_groups

kakfa-python

code

admin_client = KafkaAdminClient(bootstrap_servers='bootstrap_servers')
start = time.time()
print(len(admin_client.list_consumer_groups()))
end = time.time()
print(end-start)

output

24
60.0907678604

kafka java client

command

time bin/kafka-consumer-groups.sh --bootstrap-server bootstrap_servers --list

output

real	0m1.957s
user	0m1.536s
sys	0m0.108s

describe_consumer_groups

kakfa-python

code

admin_client = KafkaAdminClient(bootstrap_servers='bootstrap_servers')
start = time.time()
print(len(admin_client.describe_consumer_groups(['group'])))
end = time.time()
print(end-start)

output

1
30.0456149578

kafka java client

command

time bin/kafka-consumer-groups.sh --bootstrap-server bootstrap_servers --describe --group group

output

real	0m1.948s
user	0m1.780s
sys	0m0.128s

list_consumer_group_offsets

kakfa-python

code

admin_client = KafkaAdminClient(bootstrap_servers='bootstrap_servers')
start = time.time()
print(len(admin_client.list_consumer_group_offsets('group')))
end = time.time()
print(end-start)

output

3
30.0500910282

[jeffwidman]

Hmm... I'm curious whether the slowdown is in the initial bootstrapping of the client (fetching metadata, identifying broker version, etc) or in the actual calls.

Could you try running a different KafkaAdminClient command right after you instantiate it and then start your timing? That way you're measuring a fully-bootstrapped client.

To be clear, not saying this is a good thing, I would expect python to be a little slower, but not this much slower, and I'm curious where the source of the slowdown is.

Also, try setting the api_version param so that KafkaAdminClient doesn't have to probe the cluster to figure it out... see if that speeds things up.

[jeffwidman]

@jdxin0 can you try this on master?

I saw absolutely massive performance increases when fetching consumer offsets after #1823... details in #1823 (comment).

If you're still seeing the issue on latest master, I'm happy to re-open, but I suspect this should be solved for you...

[jdxin0]

@jeffwidman
I have tried the latest master version. This problem is solved .
Good work!

[nbommu1]

it works fine with single broker but same slow response list_consumer_groups() if it is cluster.