【发布时间】：2020-07-13 15:08:33
【问题描述】：
几个月前，我在我的 Kafka 链中创建了两个消费者组（每个组有 3 个消费者）：
- 第一组：从外部获取数据并将它们发送到我的主题1
- 第二组：从 topic1 消费
这没有问题。
最近，我添加了第三组以将并行化添加到我的链中：
- 对第一组的影响：也发送到 topic3（在发送到 topic1 之上）
- 新的第三组（还有 3 个消费者）：从 topic3 消费
问题：新主题 3 并未真正被消耗（在多个小时后消耗了每个主题中的 20 或 50 条消息......）=> 在第三组的 3 个分区的每个分区上存在巨大的“滞后”（从未消耗）。
在 kafka 日志中，我只能看到第三组的许多重新平衡（似乎达到 5 分钟默认 max.poll.interval.ms 但我不确定：kafka 消息未明确指定：准备重新平衡组 group3...)。 我尝试修改轮询选项，减少 max.poll.records 等的数量。减少后情况会更好，但我继续获得重新平衡...我尝试添加更多 CPU 内核（我在想对许多消费者来说，我的服务器上的 CPU）从 1 到 2，最后是 4 个 vcore：没有真正的变化，而且 htop 没有显示 CPU 内核的巨大利用率......
我只遇到新消费组的滞后/再平衡问题，消费代码和其他消费者一样...
我不知道该怎么办...关于 kafka conf、kafka CPU 的利用率或其他任何建议？
注意：所有堆栈都在 Docker 容器下
谢谢！
编辑： kafka日志示例1（生成循环不重置为0）：
...
[2020-07-15 10:52:32,029] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 365 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-319d2d85-ad11-4012-9e30-d8c94f706bbe with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 10:52:32,036] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 366 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 10:52:32,040] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 366 (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 10:54:00,552] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 10:57:32,144] INFO [GroupCoordinator 1001]: Member[group.instance.id None, member.id kafka-python-2.0.1-319d2d85-ad11-4012-9e30-d8c94f706bbe] in group group3 has left, removing it from the group (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 10:57:32,149] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 366 (__consumer_offsets-38) (reason: removing member kafka-python-2.0.1-319d2d85-ad11-4012-9e30-d8c94f706bbe on LeaveGroup) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 10:57:32,157] INFO [GroupCoordinator 1001]: Group group3 with generation 367 is now empty (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:04:00,553] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 2 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 11:06:14,173] INFO [GroupCoordinator 1001]: Dynamic Member with unknown member id joins group group3 in Empty state. Created a new member id kafka-python-2.0.1-9eae5a06-c39f-4b66-b9c6-e2e520d787c1 for this member and add to the group. (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:06:14,182] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 367 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-9eae5a06-c39f-4b66-b9c6-e2e520d787c1 with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:06:14,205] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 368 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:06:14,210] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 368 (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:11:14,233] INFO [GroupCoordinator 1001]: Member[group.instance.id None, member.id kafka-python-2.0.1-9eae5a06-c39f-4b66-b9c6-e2e520d787c1] in group group3 has left, removing it from the group (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:11:14,234] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 368 (__consumer_offsets-38) (reason: removing member kafka-python-2.0.1-9eae5a06-c39f-4b66-b9c6-e2e520d787c1 on LeaveGroup) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:11:14,235] INFO [GroupCoordinator 1001]: Group group3 with generation 369 is now empty (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:14:00,552] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 11:15:42,480] INFO [GroupCoordinator 1001]: Dynamic Member with unknown member id joins group group3 in Empty state. Created a new member id kafka-python-2.0.1-560ebdf5-4c6f-4f12-85d5-bf6e7194b712 for this member and add to the group. (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:15:42,483] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 369 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-560ebdf5-4c6f-4f12-85d5-bf6e7194b712 with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:15:42,489] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 370 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:15:42,505] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 370 (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:20:42,655] INFO [GroupCoordinator 1001]: Member[group.instance.id None, member.id kafka-python-2.0.1-560ebdf5-4c6f-4f12-85d5-bf6e7194b712] in group group3 has left, removing it from the group (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:20:42,657] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 370 (__consumer_offsets-38) (reason: removing member kafka-python-2.0.1-560ebdf5-4c6f-4f12-85d5-bf6e7194b712 on LeaveGroup) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:20:42,657] INFO [GroupCoordinator 1001]: Group group3 with generation 371 is now empty (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:24:00,552] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 11:34:00,552] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 11:36:26,840] INFO [GroupCoordinator 1001]: Dynamic Member with unknown member id joins group group3 in Empty state. Created a new member id kafka-python-2.0.1-6c853061-c4e8-4066-8940-2c7173709a96 for this member and add to the group. (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:36:26,860] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 371 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-6c853061-c4e8-4066-8940-2c7173709a96 with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:36:26,869] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 372 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:36:26,879] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 372 (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:41:26,949] INFO [GroupCoordinator 1001]: Member[group.instance.id None, member.id kafka-python-2.0.1-6c853061-c4e8-4066-8940-2c7173709a96] in group group3 has left, removing it from the group (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:41:26,952] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 372 (__consumer_offsets-38) (reason: removing member kafka-python-2.0.1-6c853061-c4e8-4066-8940-2c7173709a96 on LeaveGroup) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:41:26,953] INFO [GroupCoordinator 1001]: Group group3 with generation 373 is now empty (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:44:00,552] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 11:49:45,548] INFO [GroupCoordinator 1001]: Dynamic Member with unknown member id joins group group3 in Empty state. Created a new member id kafka-python-2.0.1-834458a8-67f7-4a0d-9056-52b6b61e79db for this member and add to the group. (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:49:45,576] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 373 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-834458a8-67f7-4a0d-9056-52b6b61e79db with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:49:45,580] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 374 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:49:45,586] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 374 (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:54:00,552] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 11:54:45,676] INFO [GroupCoordinator 1001]: Member[group.instance.id None, member.id kafka-python-2.0.1-834458a8-67f7-4a0d-9056-52b6b61e79db] in group group3 has left, removing it from the group (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:54:45,685] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 374 (__consumer_offsets-38) (reason: removing member kafka-python-2.0.1-834458a8-67f7-4a0d-9056-52b6b61e79db on LeaveGroup) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:54:45,686] INFO [GroupCoordinator 1001]: Group group3 with generation 375 is now empty (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:59:01,403] INFO [GroupCoordinator 1001]: Dynamic Member with unknown member id joins group group3 in Empty state. Created a new member id kafka-python-2.0.1-f8f4d080-73df-43bd-b49b-5b5403d15e00 for this member and add to the group. (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:59:01,432] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 375 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-f8f4d080-73df-43bd-b49b-5b5403d15e00 with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:59:01,471] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 376 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 11:59:01,481] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 376 (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:04:00,552] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 12:04:01,515] INFO [GroupCoordinator 1001]: Member[group.instance.id None, member.id kafka-python-2.0.1-f8f4d080-73df-43bd-b49b-5b5403d15e00] in group group3 has left, removing it from the group (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:04:01,518] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 376 (__consumer_offsets-38) (reason: removing member kafka-python-2.0.1-f8f4d080-73df-43bd-b49b-5b5403d15e00 on LeaveGroup) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:04:01,519] INFO [GroupCoordinator 1001]: Group group3 with generation 377 is now empty (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:14:00,552] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 12:21:11,498] INFO [GroupCoordinator 1001]: Dynamic Member with unknown member id joins group group3 in Empty state. Created a new member id kafka-python-2.0.1-43259283-cdeb-4738-aaa4-44e83542c7dc for this member and add to the group. (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:21:11,502] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 377 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-43259283-cdeb-4738-aaa4-44e83542c7dc with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:21:11,505] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 378 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:21:11,508] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 378 (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:24:00,554] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 2 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 12:26:11,680] INFO [GroupCoordinator 1001]: Member[group.instance.id None, member.id kafka-python-2.0.1-43259283-cdeb-4738-aaa4-44e83542c7dc] in group group3 has left, removing it from the group (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:26:11,811] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 378 (__consumer_offsets-38) (reason: removing member kafka-python-2.0.1-43259283-cdeb-4738-aaa4-44e83542c7dc on LeaveGroup) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:26:11,812] INFO [GroupCoordinator 1001]: Group group3 with generation 379 is now empty (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:34:00,553] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 12:34:30,547] INFO [GroupCoordinator 1001]: Dynamic Member with unknown member id joins group group3 in Empty state. Created a new member id kafka-python-2.0.1-0775e634-fe08-40e9-9ae3-7080ec21dd8a for this member and add to the group. (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:34:30,597] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 379 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-0775e634-fe08-40e9-9ae3-7080ec21dd8a with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:34:30,613] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 380 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:34:30,628] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 380 (kafka.coordinator.group.GroupCoordinator)
Kafka日志示例2（生成循环重置为0）：
...
[2020-07-15 12:10:02,637] INFO [GroupMetadataManager brokerId=1001] Group group3 transitioned to Dead in generation 2 (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 12:10:02,637] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 12:19:22,210] INFO [GroupCoordinator 1001]: Dynamic Member with unknown member id joins group group3 in Empty state. Created a new member id kafka-python-2.0.1-4ecb3653-0db8-4233-9842-710db5270491 for this member and add to the group. (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:19:22,211] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 0 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-4ecb3653-0db8-4233-9842-710db5270491 with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:19:22,212] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 1 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:19:22,214] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 1 (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:20:02,637] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 12:24:22,271] INFO [GroupCoordinator 1001]: Member[group.instance.id None, member.id kafka-python-2.0.1-4ecb3653-0db8-4233-9842-710db5270491] in group group3 has left, removing it from the group (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:24:22,272] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 1 (__consumer_offsets-38) (reason: removing member kafka-python-2.0.1-4ecb3653-0db8-4233-9842-710db5270491 on LeaveGroup) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:24:22,272] INFO [GroupCoordinator 1001]: Group group3 with generation 2 is now empty (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:25:29,398] INFO [GroupCoordinator 1001]: Dynamic Member with unknown member id joins group group3 in Empty state. Created a new member id kafka-python-2.0.1-d927d9d4-1885-4430-a84b-4cc92cb7a04e for this member and add to the group. (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:25:29,398] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 2 (__consumer_offsets-38) (reason: Adding new member kafka-python-2.0.1-d927d9d4-1885-4430-a84b-4cc92cb7a04e with group instance id None) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:25:29,399] INFO [GroupCoordinator 1001]: Stabilized group group3 generation 3 (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:25:29,401] INFO [GroupCoordinator 1001]: Assignment received from leader for group group3 for generation 3 (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:30:02,637] INFO [GroupMetadataManager brokerId=1001] Removed 0 expired offsets in 1 milliseconds. (kafka.coordinator.group.GroupMetadataManager)
[2020-07-15 12:30:29,420] INFO [GroupCoordinator 1001]: Member[group.instance.id None, member.id kafka-python-2.0.1-d927d9d4-1885-4430-a84b-4cc92cb7a04e] in group group3 has left, removing it from the group (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:30:29,420] INFO [GroupCoordinator 1001]: Preparing to rebalance group group3 in state PreparingRebalance with old generation 3 (__consumer_offsets-38) (reason: removing member kafka-python-2.0.1-d927d9d4-1885-4430-a84b-4cc92cb7a04e on LeaveGroup) (kafka.coordinator.group.GroupCoordinator)
[2020-07-15 12:30:29,421] INFO [GroupCoordinator 1001]: Group group3 with generation 4 is now empty (__consumer_offsets-38) (kafka.coordinator.group.GroupCoordinator)
EDIT2 : 添加消费者的零件代码
self.consumer = KafkaConsumer('topic1',
bootstrap_servers=brokers_env_var,
auto_offset_reset='earliest',
enable_auto_commit=True,
session_timeout_ms=14000,
heartbeat_interval_ms=2000,
group_id='group3',
max_poll_records=100,
key_deserializer=lambda x: loads(x.decode('utf-8')),
value_deserializer=lambda x: loads(x.decode('utf-8')))
try:
for message in self.consumer:
self.consumeMessage(message.value)
except Exception as error:
print('Run error - error : ' + str(error))
【问题讨论】：
-
尝试找出组3中消费者的阶段，即1）他们是否都找到了组协调员2）他们是否都发送了加入组请求3）他们是否得到了加入组请求的响应4）他们是否发送了同步请求等。您可以在此处阅读重新平衡协议 - medium.com/streamthoughts/…
-
感谢您的评论，我编辑了我的第一篇文章，并以重新平衡为例
-
从日志看来，消费者组的一名消费者不断离开该组，因此重新平衡正在进行中。请检查消费者端日志。第 3 组有多少消费者？什么是 max.poll.interval.ms？需要弄清楚消费者为什么要离开群组。
-
是.. max.poll.interval.ms 是默认值（5000s）/他们是 group3 中的 3 个消费者，并且消费者方面没有错误.../主题的 3 个分区中的每一个都非常滞后（总共 100k 条消息在数小时内只消耗了 30 条消息）。
-
您需要分析不同日志级别的消费者端日志，并找出消费者离开群组的原因。随着重新平衡的进行，在重新平衡完成之前，消费者不会从分区中读取任何内容。还有一件事我无法理解，通过添加消费者组来实现并行化。通过这种设计，消费者组（即组 2 和组 3）都将收到发布在 topic1 上的所有消息。
标签： apache-kafka kafka-consumer-api kafka-python