Backtrace Information
This section explains how to generate backtrace logs on your Exasol system.
If you are experiencing performance problems or operations that hang, you need to provide all the backtrace information for the time period when the problem occurred.
Prerequisites
You must have enough free disk space for the logs. For more information, see EXAsupport.
Procedure
The following examples use ConfD through the command-line tool confd_client, which is available on all database nodes. For more information, see ConfD.
Placeholder values are indicated with UPPERCASE characters. Replace the placeholders with your own values.
-
Connect to EXAClusterOS (COS) on the cluster using
c4 connect -t <DEPLOYMENT>[.<NODE>]/cos
. For example:If you do not specify a node, c4 will connect to the first active node in the deployment.
For more information about how to use
c4 connect
, see How to use c4. -
To find the name of the database, use the ConfD job db_list. For example:
-
To create a backtrace log, use the EXAsupport tool . Specify the start date (
-s
) and end date (-t
) using the formatYYYY-MM-DD
. For example:If the log file was created successfully, you will see the following message containing the file name:
- To disconnect from EXAClusterOS, use CTRL+D or type
exit
. -
Copy the log file to your local computer using the
scp
command (secure copy).Parameter Description $COS_PORT The SSH port for connecting to EXAClusterOS (COS). Default = 20002
To find the port number in the configuration, use
c4 config | grep CCC_PLAY_SSHD_PORT
.$KEY The filename of the SSH private key.
To find the filename in the configuration, use
c4 config | grep CCC_AWS_KEY_PAIR_FILE
.$DATABASE_IP The external IP address of the cluster node that you were connected to when creating the log file.
To find the IP addresses of all nodes, use
c4 ps
.$FILENAME The name of the log file that was generated by EXAsupport in the previous step. $LOCAL_FOLDER Path to a folder on your computer where the log file will be stored. Example
Get the necessary info:
c4 config | grep CCC_AWS_KEY_PAIR_FILE
CCC_AWS_KEY_PAIR_FILE=my_private_key.pem
c4 config | grep CCC_PLAY_SSHD_PORT
CCC_PLAY_SSHD_PORT=20002
c4 ps
N PLAY_ID NODE MEDIUM INSTANCE EXTERNAL_IP INTERNAL_IP STAGE STATE UPTIME TTL
┌─ 1 3a4a7d8d 10 awscf c5d.large 203.0.113.10 10.0.0.10 c running 04:35:15 +∞
│ 1 3a4a7d8d 11 awscf c5d.2xlarge 203.0.113.11 10.0.0.11 d running 04:35:16 +∞
└─ 1 3a4a7d8d 12 awscf c5d.2xlarge 203.0.113.12 10.0.0.12 d running 04:35:15 +∞Copy the file to your local machine:
Verification
To verify that the log was successfully copied, use the ls
command in the target folder on your local machine.
Example
ls -lahtr ~/mylogs | grep exacluster_debuginfo
-rwxr-xr-x 1 user group 9.8K Sep 20 17:38 exacluster_debuginfo_2022_08_11-23_27_20.tar.gz