Overview

The service management page containing the function area and service list is displayed.

Figure 1 Service management page
Click to enlarge

Functional Area

In the function area of the service management page, you can select a view type and filter and search by services. You can use the advanced search function to select required services based on the running status.

Service List

The service list on the service management page contains all installed services in the cluster. If the tile view mode is selected, the services will be displayed in pane style. If you select the list view mode, the services will be displayed in a table.

In this section, the Tile View is used by default.

The service list displays the running status, configuration status, role type, and number of instances of each service. On this page, you can perform some service maintenance tasks, such as starting, stopping, and restarting services.

**Table 1** Service running status
Status	Description
Normal	Indicates that the service is running properly.
Faulty	Indicates that the service cannot run properly.
Subhealthy	Indicates that some enhanced functions of the service are abnormal.
Not started	Indicates that the service is stopped.
Unknown	Indicates that the initial status of the service cannot be detected.
Starting	Indicates that the service is being started.
Stopping	Indicates that the service is being stopped.
Failed to start	Indicates that the service fails to be started.
Failed to stop	Indicates that the service fails to be stopped.

If the health status of a service is Faulty, an alarm is generated. Rectify the fault based on the alarm information.
HBase, Hive, Spark, and Loader may be in the Subhealthy state.
- If YARN is installed but is abnormal, HBase is in the Subhealthy state. If the multi-instance function is enabled, all installed HBase service instances are in the Subhealthy state.
- If HBase is installed but is abnormal, Hive, Spark, and Loader are in the Subhealthy state.
- If any HBase instance is installed but is abnormal after the multi-instance function is enabled, Loader is in the Subhealthy state.
- If an HBase instance is installed but is abnormal after the multi-instance function is enabled, the Hive and Spark instances that map to the HBase instance are in the Subhealthy state. That is, if HBase 2 is installed but is abnormal, Hive 2 and Spark2 are in the Subhealthy state.

**Table 2** Service configuration status
Status	Description
Synchronized	Indicates that all service parameter settings have taken effect in the cluster.
Expired	Indicates that the latest configuration is not synchronized and does not take effect after service parameter settings are modified. The configuration needs to be synchronized and the related services need to be restarted. You can click next to Configuration Status to view expired configuration items.
Failed	Indicates that a communication or read/write exception occurs during the parameter configuration synchronization. Use Synchronize Configuration to rectify the fault.
Synchronizing	Indicates that the service parameter configuration is being synchronized.
Unknown	Indicates that the initial status of the service cannot be detected.

You can click a service in the service list to perform simple maintenance and management operations on the service, as described in Table 3.

**Table 3** Basic management and maintenance
UI Portal	Description
Start Service	Start a specified service in the cluster.
Stop Service	Stop a specified service in the cluster.
Restart Service	Restart a specified service in the cluster. NOTE: If a service is restarted, other services that depend on this service will be unavailable. Therefore, select Restart upper-layer services. Determine whether to perform this operation based on the displayed service list. Services are restarted one by one due to their dependency. Table 4 describes the restart duration of a single service.
Service Rolling Restart	Restart a specified service in the cluster without interrupting services. For details about the parameter settings, see Table 1.
Synchronize Configuration	Enable new configuration parameters for a specified service in the cluster. Deliver new configuration parameters for services whose Configuration Status is Expired. NOTE: After some services are synchronized, restart the services for the settings to take effect.

**Table 4** Restart time
Service Name	Restart Duration	Start Duration	Remarks
CDL	2min	CDLConnector: 1min CDLService: 1min	-
ClickHouse	4min	ClickHouseServer: 2min ClickHouseBalancer: 2min	-
HDFS	10min+x	NameNode: 4 min + x DataNode: 2 min JournalNode: 2 min Zkfc: 2 min	X indicates the duration for loading NameNode metadata. About two minutes are required for each ten million files. For example, if there are 50 million files, x indicates 10 minutes. The start duration is affected by the duration for DataNode to report data blocks.
Yarn	5min+x	ResourceManager: 3 min + x NodeManager: 2 min	x indicates the time corresponding to the number of reserved tasks that need to be restored by ResourceManager. Each 10 thousand reserved tasks require one minute.
MapReduce	2min+x	JobHistoryServer: 2 min + x	x indicates the scanning duration of historical tasks. Each 100 thousand tasks take about 2.5 minutes.
Zookeeper	2min+x	quorumpeer: 2 min + x	x indicates the duration for loading Znodes. Each one million Znodes take about one minute.
Hive	3.5min	HiveServer: 3 min MetaStore: 90s WebHcat: 1 min Hiveoverall service: 3 min	-
Spark2x	5min	JobHistory2x: 5 min SparkResource2x: 5 min JDBCServer2x: 5 min	-
Flink	4min	FlinkResource: 1 min FlinkServer: 3min	-
Kafka	2min+x	Broker: 1 min + x	X indicates the data recovery duration. It takes about two minutes to start a single instance with 20000 partitions.
Storm	6min	Nimbus: 3 min UI: 1 min Supervisor: 1 min Logviewer: 1 min	-
Flume	3min	Flume: 2 min MonitorServer: 1 min	-