I am trying out adding/removing

tls

from a druid cluster. • For addition, I have added all the tls related configs to druid nodes by updating the config files. And restarted the nodes. It works fine. • However, for removing tls I removed all the tls related configs similarly, and restarted the node once. And I face the following error:

java.lang.IllegalStateException: No sslContext set, cannot do https
	at org.apache.druid.java.util.http.client.pool.ChannelResourceFactory.generate(ChannelResourceFactory.java:203) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.http.client.pool.ChannelResourceFactory.generate(ChannelResourceFactory.java:59) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.http.client.pool.ResourcePool$ResourceHolderPerKey.get(ResourcePool.java:262) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.http.client.pool.ResourcePool.take(ResourcePool.java:109) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.http.client.NettyHttpClient.go(NettyHttpClient.java:127) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.http.client.CredentialedHttpClient.go(CredentialedHttpClient.java:48) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.http.client.AbstractHttpClient.go(AbstractHttpClient.java:33) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.discovery.DruidLeaderClient.go(DruidLeaderClient.java:158) ~[druid-server-28.0.1.jar:28.0.1]
	at org.apache.druid.security.basic.authentication.db.cache.CoordinatorPollingBasicAuthenticatorCacheManager.tryFetchUserMapFromCoordinator(CoordinatorPollingBasicAuthenticatorCacheManager.java:256) ~[?:?]
	at org.apache.druid.security.basic.authentication.db.cache.CoordinatorPollingBasicAuthenticatorCacheManager.lambda$fetchUserMapFromCoordinator$1(CoordinatorPollingBasicAuthenticatorCacheManager.java:192) ~[?:?]
	at org.apache.druid.java.util.common.RetryUtils.retry(RetryUtils.java:129) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.common.RetryUtils.retry(RetryUtils.java:81) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.common.RetryUtils.retry(RetryUtils.java:163) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.common.RetryUtils.retry(RetryUtils.java:153) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.security.basic.authentication.db.cache.CoordinatorPollingBasicAuthenticatorCacheManager.fetchUserMapFromCoordinator(CoordinatorPollingBasicAuthenticatorCacheManager.java:190) ~[?:?]
	at org.apache.druid.security.basic.authentication.db.cache.CoordinatorPollingBasicAuthenticatorCacheManager.initUserMaps(CoordinatorPollingBasicAuthenticatorCacheManager.java:289) ~[?:?]
	at org.apache.druid.security.basic.authentication.db.cache.CoordinatorPollingBasicAuthenticatorCacheManager.start(CoordinatorPollingBasicAuthenticatorCacheManager.java:108) ~[?:?]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
	at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[?:?]
	at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
	at java.lang.reflect.Method.invoke(Method.java:568) ~[?:?]
	at org.apache.druid.java.util.common.lifecycle.Lifecycle$AnnotationBasedHandler.start(Lifecycle.java:446) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.java.util.common.lifecycle.Lifecycle.start(Lifecycle.java:341) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.guice.LifecycleModule$2.start(LifecycleModule.java:152) ~[druid-processing-28.0.1.jar:28.0.1]
	at org.apache.druid.cli.GuiceRunnable.initLifecycle(GuiceRunnable.java:136) ~[druid-services-28.0.1.jar:28.0.1]
	at org.apache.druid.cli.GuiceRunnable.initLifecycle(GuiceRunnable.java:94) ~[druid-services-28.0.1.jar:28.0.1]
	at org.apache.druid.cli.ServerRunnable.run(ServerRunnable.java:63) ~[druid-services-28.0.1.jar:28.0.1]
	at org.apache.druid.cli.Main.main(Main.java:112) ~[druid-services-28.0.1.jar:28.0.1]

• But when I restart all the nodes again, it becomes normal. • I am following this order to restart the nodes: https://druid.apache.org/docs/latest/operations/rolling-updates/ • What is the issue here?

Can you please check if you have removed SSL extension

simple-client-sslcontext

as well from common runtime

Yes I removed everything.

Looks Strange