Service list

This table describes the services that your system runs. Each service runs within its own Docker container. For each service, the table lists:

RAM needed per instance: The amount of RAM that, by default, the service needs on each instance on which it's deployed. For all services except for System services, this value is also the default Docker Container Memory value for the service.
Number of instances: Shows both:
- The required number of instances on which a service must run for the system to function properly.
- The recommended number of instances that you should run a service on. These are recommended minimums; if your system includes more instances, you should take advantage of them by running services on them.
Service unit cost per instance: The number of service units that it costs to run the service on one instance. This cost indicates how computationally expensive one service is compared to another.
Whether the service is persistent (that is, it must run on a specific instance) or supports floating (that is, it can run on any instance).
Whether the service has a single type or multiple.

Note: For services with both the Container Memory and Max Heap Size settings, the Container Memory setting should be larger than the Max Heap Size setting.

Service name and description	Service properties
The services perform functions related to the system's supported use cases. You can move, scale, and reconfigure these services.
Admin-App Runs the Admin App.	RAM needed per instance	N/A
	Number of instances	N/A
	Service unit cost per instance	10
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Cluster-Coordination Mesos (master) - https://mesos.apache.org Hardware resource management solution for distributed systems. How it's used Manages hardware resource allocation.	RAM needed per instance	N/A
	Number of instances	N/A
	Service unit cost per instance	1
	Persistent or floating	Persistent
	Supports volume configuration	No
	Single or multiple types	Single
Cluster-Worker Mesos (slave) - https://mesos.apache.org Hardware resource management solution for distributed systems. How it's used Receives and performs work from other services. Note: Though the Cluster-Worker service has a low service unit cost, it can at times appear to be using a large amount of CPU resources. When other services use Cluster-Worker to perform their work, Cluster-Worker reflects the CPU usage of those services.	RAM needed per instance	N/A
	Number of instances	N/A
	Service unit cost per instance	5
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Clustered-File-System https://hortonworks.com/apache/hdfs Hadoop Distributed File System. A distributed file system used for storing data. Important: The Clustered-File-System service is offered as a technology preview. Do not use it on a production system	RAM needed per instance	Data Node: 751 MB Name Node: 1024 MB Journal Node: 256 MB
	Number of instances	See Clustered-File-System service considerations
	Service unit cost per instance	Data Node: 5 Name Node: 10 Journal Node: 1
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Multiple: Data Node: Stores data Name Node: Tracks the data stored in Data Nodes Journal Node: Tracks changes made by the Name Nodes
Dashboard https://www.elastic.co/products/kibana Visualizes information stored in Elasticsearch indexes. How it's used Powers the advanced Dashboard Management service. Note: This service is in the Unconfigured state by default.	RAM needed per instance	300 MB
	Number of instances	Required: 0 Optimal: 2
	Service unit cost per instance	5
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Database http://cassandra.apache.org/ Decentralized database that can be scaled across large numbers of hardware nodes. How it's used Stores system configuration data. Also stores document discovery and failure data for workflow tasks.	RAM needed per instance	2.4 GB
	Number of instances	Required: 1 Optimal: 3
	Service unit cost per instance	10
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Index http://lucene.apache.org/solr/ Data indexing and search platform. How it's used The search engine that manages all internal search indexes.	RAM needed per instance	2 GB
	Number of instances	Required: 0 Optimal: 3 Notes: No instances are required to run this service, but without at least one, you cannot index data. If multiple copies of an index exist (with an Index Protection Level greater than one), each copy is managed by a separate instance of the Index service.
	Service unit cost per instance	25
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Logging https://www.elastic.co/products/logstash Collection engine for event data. Can perform transformations on the data it collects and then send that data to a number of outputs. How it's used Transports system logs and metrics data to the Metrics service.	RAM needed per instance	700 MB
	Number of instances	Required: 1 Optimal: 1
	Service unit cost per instance	10
	Persistent or floating	Floating
	Supports volume configuration	Yes
	Single or multiple types	Single
Message Queue https://kafka.apache.org/ Stream processing platform for handling real-time data streams. How it's used Facilitates communication between instances.	RAM needed per instance	2 GB
	Number of instances	Required: 1 Optimal: 3
	Service unit cost per instance	5
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Metrics https://www.elastic.co/ Data indexing and search platform. How it's used Stores and manages: System events Workflow performance data Workflow failure data The service maintains this information in a number of internally-managed Metrics indexes.	RAM needed per instance	2000 MB
	Number of instances	Required: 1 Optimal: 3
	Service unit cost per instance	25
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Monitor-App Powers the Monitor App.	RAM needed per instance	556 MB
	Number of instances	Required: 0 Optimal: 1 Note: Scaling the Monitor-App service does not affect any of the workflows that collect data from the systems you are monitoring. For example, if you scale the service to run on 0 instances, users cannot access the Monitor App, but HCI will continue to collect data.
	Service unit cost per instance	10
	Persistent or floating	Floating
	Supports volume configuration	Yes
	Single or multiple types	Single
Network-Proxy HAProxy - https://haproxy.org Load balancer for TCP and HTTP-based applications. How it's used Maps network requests to the instances where the applicable services are located.	RAM needed per instance	N/A
	Number of instances	N/A
	Service unit cost per instance	1
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Scheduling https://mesos.github.io/chronos/ Job scheduler for Apache Mesos. How it's used Schedules workflow tasks.	RAM needed per instance	712 MB
	Number of instances	Required: 1 Optimal: 1
	Service unit cost per instance	1
	Persistent or floating	Floating
	Supports volume configuration	Yes
	Single or multiple types	Single
Search-App Powers the Search App	RAM needed per instance	556 MB
	Number of instances	Required: 0 Optimal: 2 Note: No instances are required to run this service, but without at least one, the Search App is unavailable.
	Service unit cost per instance	10
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Sentinel Runs internal system processes and monitors the health of the other services.	RAM needed per instance	N/A
	Number of instances	N/A
	Service unit cost per instance	5
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Service-Deployment Marathon - https://mesosphere.github.io/marathon/ Orchestration platform for Mesos applications. How it's used Handles deployment of high-level services (that is, the services that you can configure).	RAM needed per instance	N/A
	Number of instances	N/A
	Service unit cost per instance	1
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Synchronization Apache Zookeeper - https://zookeeper.apache.org/ Coordinates configuration settings and other information between a number of distributed services. How it's used Coordinates actions and database operations across instances.	RAM needed per instance	N/A
	Number of instances	N/A
	Service unit cost per instance	5
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single
Watchdog Monitors the other System Services and restarts them if necessary. Also responsible for initial system startup.	RAM needed per instance	N/A
	Number of instances	N/A
	Service unit cost per instance	5
	Persistent or floating	Persistent
	Supports volume configuration	Yes
	Single or multiple types	Single