Coordinator node giving repeated warnings - insufficient active servers. Cannot balance

Hi,

I have been running 2 historical servers with the below configurations. However, I am getting repeated below Warning logs as part of Coordinator server:

2019-08-20T10:53:17,114 WARN [Coordinator-Exec–0] org.apache.druid.server.coordinator.helper.DruidCoordinatorBalancer - [node_1]: insufficient active servers. Cannot balance.

2019-08-20T10:53:17,114 WARN [Coordinator-Exec–0] org.apache.druid.server.coordinator.helper.DruidCoordinatorBalancer - [node_2]: insufficient active servers. Cannot balance.

Config file:

Historical 1

1 druid.service=druid/historical

2 druid.port=8083

3

4 # HTTP server threads

5 druid.server.http.numThreads=9

6

7

8 # Processing threads and buffers

9 druid.processing.buffer.sizeBytes=157286400

10 druid.processing.numThreads=20

11 druid.processing.numMergeBuffers=10

12

13 druid.query.groupBy.maxMergingDictionarySize=1000000

14 druid.query.groupBy.maxOnDiskStorage=6442450944

15 druid.query.groupBy.intermediateCombineDegree=8

16 druid.query.groupBy.numParallelCombineThreads=20

17

18 # Segment storage

19 druid.server.maxSize=300000000000

20

21 # Tier

22 druid.server.tier=node_1

23

24 # Segments

25 druid.segmentCache.locations=[{“path”: “<SOME_LOCATION>/segments”, “maxSize”: 300000000000}]

Historical 2

1 druid.service=druid/historical

2 druid.port=8084

3

4 # HTTP server threads

5 druid.server.http.numThreads=9

6

7

8 # Processing threads and buffers

9 druid.processing.buffer.sizeBytes=157286400

10 druid.processing.numThreads=20

11 druid.processing.numMergeBuffers=10

12

13 druid.query.groupBy.maxMergingDictionarySize=1000000

14 druid.query.groupBy.maxOnDiskStorage=6442450944

15 druid.query.groupBy.intermediateCombineDegree=8

16 druid.query.groupBy.numParallelCombineThreads=20

17

18 # Segment storage

19 druid.server.maxSize=300000000000

20

21 # Tier

22 druid.server.tier=node_2

23

24 # Segments

25 druid.segmentCache.locations=[{“path”: “<SOME_LOCATION>/segments”, “maxSize”: 300000000000}]

Do I need to have multiple historical node for a unique tier. Can please somebody help here.

Thanks,

Archit

what are the configuration of these two servers, means RAM and CPU cores? cause I think your historical tuning is misconfigured.