Configuring HBase Authorization
After configuring HBase authentication (as detailed in HBase Configuration), you must define rules on resources that is allowed to access. HBase rules can be defined individual tables, columns, and cells within a table. Cell-level authorization was added as an experimental feature in CDH 5.2 and is still considered experimental.
Understanding HBase Access Levels
- Read (R) - can read data at the given scope
- Write (W) - can write data at the given scope
- Execute (X) - can execute coprocessor endpoints at the given scope
- Create (C) - can create tables or drop tables (even those they did not create) at the given scope
- Admin (A) - can perform cluster operations such as balancing the cluster or assigning regions at the given scope
- Superuser - superusers can perform any operation available in HBase, to any resource. The user who runs HBase on your cluster is a superuser, as are any principals assigned to the configuration property hbase.superuser in hbase-site.xml on the HMaster.
- Global - permissions granted at global scope allow the admin to operate on all tables of the cluster.
- Namespace - permissions granted at namespace scope apply to all tables within a given namespace.
- Table - permissions granted at table scope apply to data or metadata within a given table.
- ColumnFamily - permissions granted at ColumnFamily scope apply to cells within that ColumnFamily.
- Cell - permissions granted at Cell scope apply to that exact cell coordinate. This allows for policy evolution along with data. To change an ACL on a specific cell, write an updated cell with new ACL to the precise coordinates of the original. If you have a multi-versioned schema and want to update ACLs on all visible versions, you'll need to write new cells for all visible versions. The application has complete control over policy evolution. The exception is append and increment processing. Appends and increments can carry an ACL in the operation. If one is included in the operation, then it will be applied to the result of the append or increment. Otherwise, the ACL of the existing cell being appended to or incremented is preserved.
- Superusers - In a production system, only the HBase user should have superuser access. In a development environment, an administrator might need superuser access to quickly control and manage the cluster. However, this type of administrator should usually be a Global Admin rather than a superuser.
Global Admins - A global admin can perform tasks and access every table in HBase. In a typical production environment, an admin should not have Read or Write permissions to data within tables.
A global admin with Admin permissions can perform cluster-wide operations on the cluster, such as balancing, assigning or unassigning regions, or calling an explicit major compaction. This is an operations role.
A global admin with Create permissions can create or drop any table within HBase. This is more of a DBA-type role.
In a production environment, it is likely that different users will have only one of Admin and Create permissions.
- Namespace Admin - a namespace admin with Create permissions can create or drop tables within that namespace, and take and restore snapshots. A namespace admin with Admin permissions can perform operations such as splits or major compactions on tables within that namespace. Prior to CDH 5.4, only global admins could create namespaces. In CDH 5.4, any user with Namespace Create privileges can create namespaces.
- Table Admins - A table admin can perform administrative operations only on that table. A table admin with Create permissions can create snapshots from that table or restore that table from a snapshot. A table admin with Admin permissions can perform operations such as splits or major compactions on that table.
- Users - Users can read or write data, or both. Users can also execute coprocessor endpoints, if given Executable permissions.
The following table shows some typical job descriptions at a hypothetical company and the permissions they might require to get their jobs done using HBase.
|Senior Administrator||Global||Admin, Create||Manages the cluster and gives access to Junior Administrators.|
|Junior Administrator||Global||Create||Creates tables and gives access to Table Administrators.|
|Table Administrator||Table||Admin||Maintains a table from an operations point of view.|
|Data Analyst||Table||Read||Creates reports from HBase data.|
|Web Application||Table||Read, Write||Puts data into HBase and uses HBase data to perform operations.|
Enable HBase Authorization
HBase authorization is built on top of the Coprocessors framework, specifically AccessController Coprocessor.
Enable HBase Authorization Using Cloudera Manager
- Go to Clusters and select the HBase cluster.
- Select Configuration.
- Search for HBase Secure Authorization and select it.
- Search for HBase Service Advanced Configuration Snippet (Safety Valve) for hbase-site.xml and enter the following into it to enable hbase.security.exec.permission.checks. Without this option, all users will continue to have access to execute endpoint coprocessors. This option is not enabled when you enable
HBase Secure Authorization for backward compatibility.
<property> <name>hbase.security.exec.permission.checks</name> <value>true</value> </property>
- Optionally, search for and configure HBase Coprocessor Master Classes and HBase Coprocessor Region Classes.
Enable HBase Authorization Using the Command Line
To enable HBase authorization, add the following properties to the hbase-site.xml file on every HBase server host (Master or RegionServer):
<property> <name>hbase.security.authorization</name> <value>true</value> </property> <property> <name>hbase.security.exec.permission.checks</name> <value>true</value> </property> <property> <name>hbase.coprocessor.master.classes</name> <value>org.apache.hadoop.hbase.security.access.AccessController</value> </property> <property> <name>hbase.coprocessor.region.classes</name> <value>org.apache.hadoop.hbase.security.token.TokenProvider,org.apache.hadoop.hbase.security.access.AccessController</value> </property>
Configure Access Control Lists for Authorization
Now that HBase has the security coprocessor enabled, you can set ACLs using the HBase shell. Start the HBase shell as usual.
The commands that control ACLs take the following form. Group names are prefixed with the @ symbol.
hbase> grant <user> <permissions> [ @<namespace> [ <table>[ <column family>[ <column qualifier> ] ] ] ] # grants permissions hbase> revoke <user> <permissions> [ @<namespace> [ <table> [ <column family> [ <column qualifier> ] ] ] # revokes permissions hbase> user_permission <table> # displays existing permissions
In the above commands, fields encased in <> are variables, and fields in  are optional. The permissions variable must consist of zero or more character from the set "RWCA".
- R denotes read permissions, which is required to perform Get, Scan, or Exists calls in a given scope.
- W denotes write permissions, which is required to perform Put, Delete, LockRow, UnlockRow, IncrementColumnValue, CheckAndDelete, CheckAndPut, Flush, or Compact in a given scope.
- X denotes execute permissions, which is required to execute coprocessor endpoints.
- C denotes create permissions, which is required to perform Create, Alter, or Drop in a given scope.
- A denotes admin permissions, which is required to perform Enable, Disable, Snapshot, Restore, Clone, Split, MajorCompact, Grant, Revoke, and Shutdown in a given scope.
Access Control List Example Commands
grant 'user1', 'RWC' grant 'user2', 'RW', 'tableA' grant 'user3', 'C', '@my_namespace'
Be sure to review the information in Understanding HBase Access Levels to understand the implications of the different access levels.