mirror of https://github.com/apache/druid.git
94 lines
4.2 KiB
Markdown
94 lines
4.2 KiB
Markdown
---
|
|
layout: doc_page
|
|
title: "Metadata Migration"
|
|
---
|
|
|
|
<!--
|
|
~ Licensed to the Apache Software Foundation (ASF) under one
|
|
~ or more contributor license agreements. See the NOTICE file
|
|
~ distributed with this work for additional information
|
|
~ regarding copyright ownership. The ASF licenses this file
|
|
~ to you under the Apache License, Version 2.0 (the
|
|
~ "License"); you may not use this file except in compliance
|
|
~ with the License. You may obtain a copy of the License at
|
|
~
|
|
~ http://www.apache.org/licenses/LICENSE-2.0
|
|
~
|
|
~ Unless required by applicable law or agreed to in writing,
|
|
~ software distributed under the License is distributed on an
|
|
~ "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
|
|
~ KIND, either express or implied. See the License for the
|
|
~ specific language governing permissions and limitations
|
|
~ under the License.
|
|
-->
|
|
|
|
# Metadata Migration
|
|
|
|
If you have been running an evaluation Druid cluster using the built-in Derby metadata storage and wish to migrate to a
|
|
more production-capable metadata store such as MySQL or PostgreSQL, this document describes the necessary steps.
|
|
|
|
## Shut down cluster services
|
|
|
|
To ensure a clean migration, shut down the non-coordinator services to ensure that metadata state will not
|
|
change as you do the migration.
|
|
|
|
When migrating from Derby, the coordinator processes will still need to be up initially, as they host the Derby database.
|
|
|
|
## Exporting metadata
|
|
|
|
Druid provides an [Export Metadata Tool](../operations/export-metadata.html) for exporting metadata from Derby into CSV files
|
|
which can then be imported into your new metadata store.
|
|
|
|
The tool also provides options for rewriting the deep storage locations of segments; this is useful
|
|
for [deep storage migration](../operations/deep-storage-migration.html).
|
|
|
|
Run the `export-metadata` tool on your existing cluster, and save the CSV files it generates. After a successful export, you can shut down the coordinator.
|
|
|
|
## Initializing the new metadata store
|
|
|
|
### Create database
|
|
|
|
Before importing the existing cluster metadata, you will need to set up the new metadata store.
|
|
|
|
The [MySQL extension](../development/extensions-core/mysql.html) and [PostgreSQL extension](../development/extensions-core/postgresql.html) docs have instructions for initial database setup.
|
|
|
|
### Update configuration
|
|
|
|
Update your Druid runtime properties with the new metadata configuration.
|
|
|
|
### Create Druid tables
|
|
|
|
Druid provides a `metadata-init` tool for creating Druid's metadata tables. After initializing the Druid database, you can run the commands shown below from the root of the Druid package to initialize the tables.
|
|
|
|
In the example commands below:
|
|
|
|
- `lib` is the the Druid lib directory
|
|
- `extensions` is the Druid extensions directory
|
|
- `base` corresponds to the value of `druid.metadata.storage.tables.base` in the configuration, `druid` by default.
|
|
- The `--connectURI` parameter corresponds to the value of `druid.metadata.storage.connector.connectURI`.
|
|
- The `--user` parameter corresponds to the value of `druid.metadata.storage.connector.user`.
|
|
- The `--password` parameter corresponds to the value of `druid.metadata.storage.connector.password`.
|
|
|
|
#### MySQL
|
|
|
|
```bash
|
|
cd ${DRUID_ROOT}
|
|
java -classpath "lib/*" -Dlog4j.configurationFile=conf/druid/cluster/_common/log4j2.xml -Ddruid.extensions.directory="extensions" -Ddruid.extensions.loadList=[\"mysql-metadata-storage\"] -Ddruid.metadata.storage.type=mysql org.apache.druid.cli.Main tools metadata-init --connectURI="<mysql-uri>" --user <user> --password <pass> --base druid
|
|
```
|
|
|
|
#### PostgreSQL
|
|
|
|
```bash
|
|
cd ${DRUID_ROOT}
|
|
java -classpath "lib/*" -Dlog4j.configurationFile=conf/druid/cluster/_common/log4j2.xml -Ddruid.extensions.directory="extensions" -Ddruid.extensions.loadList=[\"postgresql-metadata-storage\"] -Ddruid.metadata.storage.type=postgresql org.apache.druid.cli.Main tools metadata-init --connectURI="<postgresql-uri>" --user <user> --password <pass> --base druid
|
|
```
|
|
|
|
### Import metadata
|
|
|
|
After initializing the tables, please refer to the [import commands](../operations/export-metadata.html#importing-metadata) for your target database.
|
|
|
|
### Restart cluster
|
|
|
|
After importing the metadata successfully, you can now restart your cluster.
|
|
|