Meta Store
This section describes the openLooKeng meta store. Meta store is used to store metadata. Meta store supports to store metadata in the RDBMS or HDFS.
Configuring Meta Store
Create the meta store property file etc/hetu-metastore.properties
first.
RDBMS Storage
Add the following contents in hetu-metastore.properties
:
hetu.metastore.type=jdbc
hetu.metastore.db.url=jdbc:mysql://....
hetu.metastore.db.user=root
hetu.metastore.db.password=123456
hetu.metastore.cache.type=local
The above properties are described below:
hetu.metastore.type
:The type of meta store, setjdbc
to use RDBMS storage.hetu.metastore.db.url
:URL of RDBMS to connect to.hetu.metastore.db.user
:User name of RDBMS to connect to.hetu.metastore.db.password
:Password of RDBMS to connect to.hetu.metastore.cache.type
: Select the cache model, where local is the local cache and global is the distributed cache.
HDFS Storage
Add the following contents in hetu-metastore.properties
:
hetu.metastore.type=hetufilesystem
hetu.metastore.hetufilesystem.profile-name=hdfs-config-metastore
hetu.metastore.hetufilesystem.path=/etc/openlookeng/metastore
The above properties are described below:
hetu.metastore.type
:The type of meta store, sethetufilesystem
to use HDFS storage.hetu.metastore.hetufilesystem.profile-name
:The profile name of file system.hetu.metastore.hetufilesystem.path
:The path of metastore storage in the file system.
Meta Store Cache
openLooKeng can be configured to enable metadata caching. After the metadata caching is enabled, metadata will be cached in the memory to improve access efficiency for the next access.
Add the following contents in hetu-metastore.properties
:
hetu.metastore.cache.size=10000
hetu.metastore.cache.ttl=4h
The above properties are described below:
hetu.metastore.cache.size
:Set the max metastore cache size, default value 10000.hetu.metastore.cache.ttl
:Set ttl for metastore cache, default value 0 (metadata caching is disabled).