KB-1687 Unable to connect to other servers in HA environment

Devon Lee — Tue, 24 May 2022 15:16:12 GMT

Current Revision posted to Appian Knowledge Base by Devon Lee on 5/24/2022 3:16:12 PM

Symptoms

During start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up.
Following errors are observed in service_manager.log located in <APPIAN-HOME>/logs/:

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to <server's IP address>:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

Improper network connectivity can lead to this issue. Active firewalls on one or more of the servers running Appian can prevent the servers from communicating with each other.

Action

Check for active firewall rules or other network configuration which is preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: kafka, engines, infrastructure, HA

KB-1687 Unable to connect to other servers in HA environment

Parmida Borhani — Fri, 31 Aug 2018 03:14:25 GMT

Revision 14 posted to Appian Knowledge Base by Parmida Borhani on 8/31/2018 3:14:25 AM

Symptoms

During start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up.
Following errors are observed in service_manager.log located in <APPIAN-HOME>/logs/:

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to <server's IP address>:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

Improper network connectivity can lead to this issue. Active firewalls on one or more of the servers running Appian can prevent the servers from communicating with each other.

Action

Check for active firewall rules or other network configuration which is preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: kafka, engines, infrastructure, HA

KB-1687 Unable to connect to other servers in HA environment

Parmida Borhani — Thu, 30 Aug 2018 23:13:52 GMT

Revision 13 posted to Appian Knowledge Base by Parmida Borhani on 8/30/2018 11:13:52 PM

Symptoms

During start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up.
Following errors are observed in service_manager.log located in <APPIAN-HOME>/logs/:

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to <server's IP address>:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

Improper network connectivity can lead to this issue. Active firewalls on one or more of the servers running Appian can prevent the servers from communicating with each other.

Action

Check for active firewall rules or other network configuration which is preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: kafka, engines, shared components, infrastructure, HA

DRAFT KB-XXXX Unable to connect to other servers in HA environment

Anirudh Rathi — Thu, 30 Aug 2018 14:31:38 GMT

Revision 12 posted to Appian Knowledge Base by Anirudh Rathi on 8/30/2018 2:31:38 PM

Symptoms

During start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up.
Following errors are observed in service_manager.log located in <APPIAN-HOME>/logs/:

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to <server's IP address>:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

Improper network connectivity can lead to this issue. Active firewalls on one or more of the servers running Appian can prevent the servers from communicating with each other.

Action

Check for active firewall rules or other network configuration which is preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: kafka, engines, shared components, infrastructure

DRAFT KB-XXXX Unable to connect to other servers in HA environment

Anirudh Rathi — Thu, 30 Aug 2018 14:29:15 GMT

Revision 11 posted to Appian Knowledge Base by Anirudh Rathi on 8/30/2018 2:29:15 PM

Symptoms

During start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up.
Following errors are observed in service_manager.log located in <APPIAN-HOME>/logs/:

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to <server's IP address>:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

Improper network configurations can lead to this issue. Active firewalls on one or more of the servers running Appian can prevent the servers from communicating with each other.

Action

Check for active firewall rules or other network configuration which is preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: kafka, engines, shared components, infrastructure

DRAFT KB-XXXX Unable to connect to other servers in HA environment

Tom Ryan — Wed, 29 Aug 2018 19:36:59 GMT

Revision 10 posted to Appian Knowledge Base by Tom Ryan on 8/29/2018 7:36:59 PM

Symptoms

During start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up.
Following errors are observed in service_manager.log located in <APPIAN-HOME>/logs/:

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to <server's IP address>:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

Active firewalls on one or more of the servers running Appian is preventing the servers from communicating with each other

Action

Check for active firewall rules preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: kafka, engines, shared components, infrastructure

DRAFT KB-XXXX Unable to connect to other servers in HA environment

Parmida Borhani — Sun, 26 Aug 2018 21:43:08 GMT

Revision 9 posted to Appian Knowledge Base by Parmida Borhani on 8/26/2018 9:43:08 PM

Symptoms

During start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up.
Following errors are observed in service_manager.log located in <APPIAN-HOME>/logs/:

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 172.31.0.14:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

Active firewalls on one or more of the servers running Appian is preventing the servers from communicating with each other

Action

Check for active firewall rules preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: kafka, engines, shared components, infrastructure

DRAFT KB-XXXX Unable to connect to other servers in HA environment

Anirudh Rathi — Fri, 24 Aug 2018 10:52:14 GMT

Revision 8 posted to Appian Knowledge Base by Anirudh Rathi on 8/24/2018 10:52:14 AM

Symptoms

During the start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up
Following errors are observed in service_manager.log located in <APPIAN-HOME>/logs/

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 172.31.0.14:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

Active firewalls on one or more of the servers running Appian is preventing the servers from communicating with each other

Action

Check for active firewall rules preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: kafka, engines, shared components, infrastructure

DRAFT KB-XXXX Unable to connect to other servers in HA environment.

Parmida Borhani — Wed, 22 Aug 2018 21:28:39 GMT

Revision 7 posted to Appian Knowledge Base by Parmida Borhani on 8/22/2018 9:28:39 PM

Symptoms

During the start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up
Following errors are observed in <APPIAN-HOME>/logs/service_manager.logs

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 172.31.0.14:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

The issue is caused because of active firewalls on one or more servers.

Action

Check for active firewall rules preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: kafka, engines, shared components, infrastructure

DRAFT KB-XXXX Unable to connect to other servers in HA environment.

Anirudh Rathi — Wed, 22 Aug 2018 16:59:57 GMT

Revision 6 posted to Appian Knowledge Base by Anirudh Rathi on 8/22/2018 4:59:57 PM

Symptoms

During the start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up
Following errors are observed in <APPIAN-HOME>/logs/service_manager.logs

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 172.31.0.14:9092 (id: 2 rack: null) failed
...
Waiting for <number of servers> brokers to be available. 
...
Unable to connect to Kafka broker <server's IP address>

Cause

The issue is caused because of active firewalls on one or more servers.

Action

Check for active firewall rules preventing the servers from communicating with each other.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: August 2018

Tags: shared components, infrastructure

DRAFT KB-XXXX Unable to connect to other servers in HA environment.

Anirudh Rathi — Tue, 21 Aug 2018 17:14:13 GMT

Revision 5 posted to Appian Knowledge Base by Anirudh Rathi on 8/21/2018 5:14:13 PM

Symptoms

During the start-up servers are not able to find Kafka broker on other servers.
Unable to telnet to other servers on the Kafka port.
The engines fail to start up
Following errors are observed in <APPIAN-HOME>/logs/service_manager.logs

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 172.31.0.14:9092 (id: 2 rack: null) failed

Waiting for <number of servers> brokers to be available.

Unable to connect to Kafka broker <server's IP address>

Cause

The issue is caused because of active firewalls on one or more servers.

Action

Check for active firewall rules preventing the servers from communicating with each other.

Tags: shared components, infrastructure

DRAFT INT-XXXX Unable to connect to other servers in HA environment.

Anirudh Rathi — Fri, 17 Aug 2018 20:29:15 GMT

Revision 1 posted to Appian Knowledge Base by Anirudh Rathi on 8/17/2018 8:29:15 PM

Symptoms

Servers not able to find Kafka broker on other servers.
Unable to telnet to other servers, ping goes through fine.
Engine start-up stuck.
Errors include :

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 172.31.0.14:9092 (id: 2 rack: null) failed

Waiting for <number of servers> brokers to be available.

Unable to connect to Kafka broker <server's IP address>

Cause

This issue is caused because of active firewalls on one or more servers.

Action

Check the firewall status on the server and turn it off.

On Linux run the command sudo systemctl status firewalld in order to check status of firewall and run the command sudo systemctl stop firewalld to stop it.

Tags: shared components, infrastructure

DRAFT KB-XXXX Unable to connect to other servers in HA environment.

Anirudh Rathi — Fri, 17 Aug 2018 16:39:20 GMT

Revision 4 posted to Appian Knowledge Base by Anirudh Rathi on 8/17/2018 4:39:20 PM

Symptoms

Servers unable to find Kafka broker on other servers.
Unable to telnet to other servers, ping goes through fine.
Engine start-up stuck.
Errors include :

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 172.31.0.14:9092 (id: 2 rack: null) failed

Waiting for <number of servers> brokers to be available.

Unable to connect to Kafka broker <server's IP address>

Cause

This issue is caused because of active firewalls on one or more servers.

Action

Check the firewall status on the servers and turn it off.

On Linux run the command sudo systemctl status firewalld in order to check status of firewall and run the command sudo systemctl stop firewalld to stop it.

Tags: shared components, infrastructure

DRAFT KB-XXXX Unable to connect to other servers in HA environment.

Anirudh Rathi — Fri, 17 Aug 2018 16:36:05 GMT

Revision 3 posted to Appian Knowledge Base by Anirudh Rathi on 8/17/2018 4:36:05 PM

Symptoms

Servers not able to find Kafka broker on other servers.
Unable to telnet to other servers, ping goes through fine.
Engine start-up stuck.
Errors include :

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 172.31.0.14:9092 (id: 2 rack: null) failed

Waiting for <number of servers> brokers to be available.

Unable to connect to Kafka broker <server's IP address>

Cause

This issue is caused because of active firewalls on one or more servers.

Action

Check the firewall status on the servers and turn it off.

On Linux run the command sudo systemctl status firewalld in order to check status of firewall and run the command sudo systemctl stop firewalld to stop it.

Tags: shared components, infrastructure

DRAFT INT-XXXX Unable to connect to other servers in HA environment.

Anirudh Rathi — Fri, 17 Aug 2018 16:30:06 GMT

Revision 2 posted to Appian Knowledge Base by Anirudh Rathi on 8/17/2018 4:30:06 PM

Symptoms

Servers not able to find Kafka broker on other servers.
Unable to telnet to other servers, ping goes through fine.
Engine start-up stuck.
Errors include :

WARN [ReplicaFetcherThread-0-2], Error in fetch kafka.server.ReplicaFetcherThread$FetchRequest@3905d112 (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 172.31.0.14:9092 (id: 2 rack: null) failed

Waiting for <number of servers> brokers to be available.

Unable to connect to Kafka broker <server's IP address>

Cause

This issue is caused because of active firewalls on one or more servers.

Action

Check the firewall status on the servers and turn it off.

On Linux run the command sudo systemctl status firewalld in order to check status of firewall and run the command sudo systemctl stop firewalld to stop it.

Tags: shared components, infrastructure