Migrating OpenResty Edge Log Server Database Data

When the database space used by OpenResty Edge Log Server is insufficient or data needs to be migrated to other devices, you can refer to this document for operation. We provide three migration methods. Please choose the most suitable solution based on your actual situation.

Note: The following operations involve deletion. Please operate with caution to avoid accidentally deleting important data.

# Method 1: Migrating the Complete Data Directory

# Applicable Scenarios

• Insufficient hard disk space, wanting to migrate data to a new hard disk on the same machine.
• Or insufficient hard disk space, wanting to migrate to a hard disk on another machine.
• Or no disk space issues, simply wanting to perform data migration.
• Suitable for local migration or cross-machine migration.

# Steps for Migration Between Different Hard Disks on the Same Machine

1. If the Log Server database service is still working normally, stop the Log Server database service to avoid data inconsistency:

   sudo systemctl stop openresty-postgresql12
   

2. Copy the data to a hard disk with sufficient space:

   sudo cp -p -R /var/postgres12/data/ /path/to/new/data
   

3. Rename the original data directory:

   sudo mv /var/postgres12/data/ /var/postgres12/data-bak
   

4. Create a symbolic link: (If space is severely insufficient, you can delete some logs or other files to free up space)

   sudo ln -s /path/to/new/data /var/postgres12/data
   

5. After confirming that the new data is correct, you can delete the old data:

   sudo rm -rf /var/postgres12/data-bak
   

6. (Optional) Restart the Log Server database service:

   sudo systemctl start openresty-postgresql12
   

# Steps for Cross-Machine Migration

1. Stop the Log Server database service on the source machine to avoid data inconsistency:

   sudo systemctl stop openresty-postgresql12
   

2. Install the Log Server database service on the target machine; refer to the document: https://doc.openresty.com/en/edge/edge-installation-upgrade/edge-installation/

3. Stop the Log Server database service on the target machine:

   sudo systemctl stop openresty-postgresql12
   

4. Delete or move the initial data on the target machine: (Please triple-check the machine you are operating on to avoid accidentally deleting valid data)

   Delete:

   sudo rm -rf /var/postgres12/data
   

   Move:

   sudo mv /var/postgres12/data /var/postgres12/data-init
   

5. Use a secure file transfer method (such as scp or rsync) to copy data from the source machine to the target machine:

   scp:

   scp -r /var/postgres12/data user@target_host:/var/postgres12/data
   

   rsync:

   rsync -avz --owner --group --perms /var/postgres12/data user@target_host:/var/postgres12/data
   

6. Restart the database service on the target machine:

   sudo systemctl restart openresty-postgresql12
   

7. Log in to the machine where the Log Server is located and modify the configuration to use the new database service:

   sudo vi /usr/local/oredge-log-server/conf/config.ini
   

# Method 2: Migration Using Master-Slave Replication

# Applicable Scenarios

• The Log Server database service is currently running normally.
• Suitable for cross-machine migration.

# Operation Steps

1. Install the Log Server database service on the target machine; refer to the document: https://doc.openresty.com/en/edge/edge-installation-upgrade/edge-installation/

2. Configure the source machine as the master and the target machine as the slave according to the document Configuring OpenResty Edge Database High Availability with Interactive Scripts or OpenResty Edge Database High Availability.

3. Stop the master on the source machine:

   sudo systemctl stop openresty-postgresql12
   

4. Promote the slave to master on the target machine:

   sudo -u postgres /usr/local/openresty-postgresql12/bin/pg_ctl promote -D /var/postgres12/data
   

5. Log in to the machine where the Log Server is located and modify the configuration to use the new database service:

   sudo vi /usr/local/oredge-log-server/conf/config.ini
   

# Method 3: Migration by Exporting and Importing Data

# Applicable Scenarios

• The Log Server database service is currently running normally.
• There is enough space on the source machine to save the exported data.
• Suitable for cross-machine migration.

# Operation Steps

1. Stop the Log Server service to prevent new data from being written to the database:

   sudo systemctl stop oredge-log-server
   

2. Export data from the source machine:

   /usr/local/openresty-postgresql12/bin/pg_dump or_edge_log_server -C -Upostgres | gzip > or_edge_log_server-`date +%F`.gz
   

3. Install the Log Server database service on the target machine; refer to the document: https://doc.openresty.com/en/edge/edge-installation-upgrade/edge-installation/

4. Stop the Log Server database service on the target machine:

   sudo systemctl stop openresty-postgresql12
   

5. Delete the initial data on the target machine: (Please triple-check the machine you are operating on to avoid accidentally deleting valid data)

   sudo rm -rf /var/postgres12/data
   

6. Transfer the exported data to the target machine

7. Import data on the target machine:

   zcat or_edge_log_server-{date}.gz | /usr/local/openresty-postgresql12/bin/psql -Upostgres
   

8. Start the database service on the target machine:

   sudo systemctl start openresty-postgresql12
   

9. Modify the Log Server configuration to use the new database service:

   sudo vi /usr/local/oredge-log-server/conf/config.ini