[KNOX-1011] Add ldap.port system property to configure LDAP demo server port

• Type: Improvement
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 0.12.0
• Fix Version/s: 1.2.0
• Component/s: KnoxSSO
• Assignee: Attila Csoma
• Reporter: Ayub Pathan
• Created: 31/Aug/17 17:50
• Updated: 28/Mar/19 13:57
• Resolved: 20/Oct/18 01:50

Description

[[Background]]

Problem: Knox demo LDAP server fails to start intermittently(happening more frequently these days), resulting in knox tests failures. LDAP server fails to start because port 33389, which it uses for listening incoming connections is already occupied on the machine.

RCA:

Question: why are we seeing zookeeper node using 33389 port?

• ZooKeeper has the notion of ephemeral nodes. These ephemeral znodes exists as long as the session that created the znode is active. When the session ends the znode is deleted. These ephemeral nodes make use of ephemeral ports depending on the system configuration.

This ephemeral port is taken from the range defined by the output of the following command.

[root@ctr-e134-1499953498516-111711-01-000004 ~]# sysctl net.ipv4.ip_local_port_range
net.ipv4.ip_local_port_range = 32768	61000
[root@ctr-e134-1499953498516-111711-01-000004 ~]#

These ephemeral znodes exists as long as the session that created the znode is active. This is the reason we are seeing zookeeper nodes using 33389 port randomly sometimes, which is resulting in LDAP server startup failures.