ALM-12043 DNS Parsing Duration Exceeds the Threshold

Alarm Description

The system checks the DNS parsing duration every 30 seconds. This alarm is generated when the DNS parsing duration exceeds the threshold (the default threshold is 1,000 ms) for consecutive X times (6 by default).

When Trigger Count is set to 1, this alarm is cleared if the DNS parsing duration is less than or equal to the threshold. When Trigger Count is set to a value greater than 1, this alarm is cleared if the DNS parsing duration is less than or equal to 90% of the threshold.

This section applies only to MRS 3.6.0-LTS.1 or later.

Alarm Attributes

Alarm Parameters

Impact on the System

• Kerberos-based secondary authentication is slow.
• The ZooKeeper service is abnormal.
• The node is faulty.

Possible Causes

• The DNS server is faulty or the DNS configuration is incorrect.
• The network is congested or the bandwidth is insufficient.

Handling Procedure

Check whether the DNS server is faulty or the DNS configuration is incorrect.

1. On the node for which the alarm is generated, check whether the IP address of the DNS server can be pinged.
   • If yes, refresh the DNS cache.
   • If no, the network cannot reach the DNS server. Change the IP address to an available one.

2. Wait for 2 minutes and check whether the alarm is cleared.
   • If yes, no further action is required.
   • If no, go to Step 3.

Check whether the network is congested or the bandwidth is insufficient.

3. Log in to the node for which the alarm is generated as the root user and run the following command to check whether the value in the %ifutil column is close to 1.00 (100%).

   sar -n DEV 1 1

   • If yes, go to Step 4.
   • If no, go to Step 6.

4. Contact O&M engineers to check whether there is abnormal traffic. If yes, rectify the fault.
5. Wait for 2 minutes and check whether the alarm is cleared.
   • If yes, no further action is required.
   • If no, go to Step 6.

Collect fault information.

6. On MRS Manager, click O&M. On the displayed page, choose Log > Download.
7. Select OmmServer and NodeAgent for Service. Select the host name recorded in the alarm location information for Hosts.
8. Click the edit icon in the upper right corner, and set Start Date and End Date for log collection to 10 minutes ahead of and after the alarm generation time, respectively. Then, click Download.
9. Send the collected fault logs to O&M engineers for help.

Alarm Clearance

This alarm is automatically cleared after the fault is rectified.

Related Information

None