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Upgrade TiDB Using TiUP

This document is targeted for users who want to upgrade from TiDB 4.0 versions to TiDB 5.0 versions, or from TiDB 5.0 to a later version.

If your cluster to upgrade is v3.1 or an earlier version (v3.0 or v2.1), you need to upgrade your cluster first to v4.0 and then to v5.0. You cannot upgrade your cluster across a major version or versions.

Upgrade caveat

  • After the upgrade, rolling back to 4.0 or earlier versions is not supported.
  • For the v4.0 cluster managed using TiDB Ansible, you need to import the cluster to TiUP (tiup cluster) for new management according to Upgrade TiDB Using TiUP (v4.0). Then you can upgrade the cluster to v5.0 according to this document.
  • To update versions earlier than 3.0 to 5.0:
    1. Update this version to 3.0 using TiDB Ansible.
    2. Use TiUP (tiup cluster) to import the TiDB Ansible configuration.
    3. Update the 3.0 version to 4.0 according to Upgrade TiDB Using TiUP (v4.0).
    4. Then you can upgrade the cluster to v5.0 according to this document.
  • Support upgrading the versions of TiDB Binlog, TiCDC, TiFlash, and other components.

Note:

Do not execute any DDL request during the upgrade, otherwise an undefined behavior issue might occur.

Preparations

This section introduces the preparation works needed before upgrading your TiDB cluster, including upgrading TiUP and the TiUP Cluster component.

Step 1: Upgrade TiUP or TiUP offline mirror

Before upgrading your TiDB cluster, you first need to upgrade TiUP or TiUP mirror.

Upgrade TiUP and TiUP Cluster

Note:

If the control machine of the cluster to upgrade cannot access https://tiup-mirrors.pingcap.com, skip this section and see Upgrade TiUP offline mirror.

  1. Upgrade the TiUP version. It is recommended that the TiUP version is 1.4.0 or later.

    tiup update --self
    tiup --version
  2. Upgrade the TiUP Cluster version. It is recommended that the TiUP Cluster version is 1.4.0 or later.

    tiup update cluster
    tiup cluster --version

Upgrade TiUP offline mirror

Note:

If the cluster to upgrade was deployed not using the offline method, skip this step.

Refer to Deploy a TiDB Cluster Using TiUP - Deploy TiUP offline to download the TiUP mirror of the new version and upload it to the control machine. After executing local_install.sh, TiUP will complete the overwrite upgrade.

tar xzvf tidb-community-server-${version}-linux-amd64.tar.gz
sh tidb-community-server-${version}-linux-amd64/local_install.sh
source /home/tidb/.bash_profile

After the overwrite upgrade, execute the following command to upgrade the TiUP Cluster component.

tiup update cluster

Now, the offline mirror has been upgraded successfully. If an error occurs during TiUP operation after the overwriting, it might be that the manifest is not updated. You can try rm -rf ~/.tiup/manifests/* before running TiUP again.

Step 2: Edit TiUP topology configuration file

Note:

Skip this step if one of the following situations applies:

  • You have not modified the configuration parameters of the original cluster. Or you have modified the configuration parameters using tiup cluster but no more modification is needed.
  • After the upgrade, you want to use v5.0's default parameter values for the unmodified configuration items.
  1. Enter the vi editing mode to edit the topology file:

    tiup cluster edit-config <cluster-name>
  2. Refer to the format of topology configuration template and fill the parameters you want to modify in the server_configs section of the topology file.

  3. After the modification, enter : + w + q to save the change and exit the editing mode. Enter Y to confirm the change.

Note:

Before you upgrade the cluster to v5.0, make sure that the parameters you have modified in v4.0 are compatible in v5.0. For details, see TiKV Configuration File.

The following three TiKV parameters are obsolete in TiDB v5.0. If the following parameters have been configured in your original cluster, you need to delete these parameters through edit-config:

  • pessimistic-txn.enabled
  • server.request-batch-enable-cross-command
  • server.request-batch-wait-duration

Step 3: Check the health status of the current cluster

To avoid the undefined behaviors or other issues during the upgrade, it is recommended to check the health status of Regions of the current cluster before the upgrade. To do that, you can use the check sub-command.

tiup cluster check <cluster-name> --cluster

After the command is executed, the "Region status" check result will be output.

  • If the result is "All Regions are healthy", all Regions in the current cluster are healthy and you can continue the upgrade.
  • If the result is "Regions are not fully healthy: m miss-peer, n pending-peer" with the "Please fix unhealthy regions before other operations." prompt, some Regions in the current cluster are abnormal. You need to troubleshoot the anomalies until the check result becomes "All Regions are healthy". Then you can continue the upgrade.

Perform a rolling upgrade to the TiDB cluster

This section describes how to perform a rolling upgrade to the TiDB cluster and how to verify the version after the upgrade.

Upgrade the TiDB cluster to a specified version

You can upgrade your cluster in one of the two ways: online upgrade and offline upgrade.

By default, TiUP Cluster upgrades the TiDB cluster using the online method, which means that the TiDB cluster can still provide services during the upgrade process. With the online method, the leaders are migrated one by one on each node before the upgrade and restart. Therefore, for a large-scale cluster, it takes a long time to complete the entire upgrade operation.

If your application has a maintenance window for the database to be stopped for maintenance, you can use the offline upgrade method to quickly perform the upgrade operation.

Online upgrade

tiup cluster upgrade <cluster-name> <version>

For example, if you want to upgrade the cluster to v5.0.4:

tiup cluster upgrade <cluster-name> v5.0.4

Note:

  • Performing a rolling upgrade to the cluster will upgrade all components one by one. During the upgrade of TiKV, all leaders in a TiKV instance are evicted before stopping the instance. The default timeout time is 5 minutes (300 seconds). The instance is directly stopped after this timeout time.

  • To perform the upgrade immediately without evicting the leader, specify --force in the command above. This method causes performance jitter but not data loss.

  • To keep a stable performance, make sure that all leaders in a TiKV instance are evicted before stopping the instance. You can set --transfer-timeout to a larger value, for example, --transfer-timeout 3600 (unit: second).

Offline upgrade

  1. Before the offline upgrade, you first need to stop the entire cluster.

    tiup cluster stop <cluster-name>
  2. Use the upgrade command with the --offline option to perform the offline upgrade.

    tiup cluster upgrade <cluster-name> <version> --offline
  3. After the upgrade, the cluster will not be automatically restarted. You need to use the start command to restart it.

    tiup cluster start <cluster-name>

Verify the cluster version

Execute the display command to view the latest cluster version TiDB Version:

tiup cluster display <cluster-name>
Cluster type:       tidb
Cluster name:       <cluster-name>
Cluster version:    v5.0.4

Note:

By default, TiUP and TiDB share usage details with PingCAP to help understand how to improve the product. For details about what is shared and how to disable the sharing, see Telemetry.

FAQ

This section describes common problems encountered when updating the TiDB cluster using TiUP.

If an error occurs and the upgrade is interrupted, how to resume the upgrade after fixing this error?

Re-execute the tiup cluster upgrade command to resume the upgrade. The upgrade operation restarts the nodes that have been previously upgraded. If you do not want the upgraded nodes to be restarted, use the replay sub-command to retry the operation:

  1. Execute tiup cluster audit to see the operation records:

    tiup cluster audit

    Find the failed upgrade operation record and keep the ID of this operation record. The ID is the <audit-id> value in the next step.

  2. Execute tiup cluster replay <audit-id> to retry the corresponding operation:

    tiup cluster replay <audit-id>

The evict leader has waited too long during the upgrade. How to skip this step for a quick upgrade?

You can specify --force. Then the processes of transferring PD leader and evicting TiKV leader are skipped during the upgrade. The cluster is directly restarted to update the version, which has a great impact on the cluster that runs online. Here is the command:

tiup cluster upgrade <cluster-name> <version> --force

How to update the version of tools such as pd-ctl after upgrading the TiDB cluster?

You can upgrade the tool version by using TiUP to install the ctl component of the corresponding version:

tiup install ctl:v5.0.4

TiDB 5.0 compatibility changes

See TiDB 5.0 GA Release Notes for the compatibility changes.