The NetScaler MAS datasbase is integrated with the server, and the server manages all the key processes, such as data collection, NITRO calls. In its data store, the server stores an inventory of instance details, such as host name, software version, running and saved configuration, certificate details, entities configured on the instance, and so on. A single server deployment is suitable if you want to process small amounts of traffic or store data for a limited time.
Currently, NetScaler MAS supports two types of NetScaler MAS server deployments: single server and high availability.
This document includes the following information:
The following image shows the different subsystems within NetScaler MAS and how communication happens between the NetScaler MAS server and managed instances.
The Service subsystem in NetScaler MAS acts as a web server that handles HTTP(s) requests and responses that are sent to subsytems within NetScaler MAS from the GUI or API, using ports 80 and 443. These requests are sent to the subsystems over the message bus (Message Processing System) by using the IPC (Inter-process Communication) mechanism. A request is sent to the Control subsystem, which either processes the information or sends it to the appropriate subsystem. Each of the other subsystems—Inventory, Stylebooks, Data Collector, Configuration, AppFlow Decoder, AppFlow Analytics, Performance, Events, Entities, SLA Manager, Provisioner, and Journal—has a specific role.
Instance plug-ins are shared libraries that are unique to each instance type supported by NetScaler MAS. Information is transferred between NetScaler MAS and managed instances by using NITRO calls, or through the SNMP, Secure Shell (SSH), or Secure Copy (SCP) protocol. This information is then processed and stored in the internal database (Data Store).
NetScaler MAS polls managed instances to collect information. The following list describes the various kinds of polling that occur between NetScaler MAS and managed instances, the protocols used to collect this information, and whether the polling intervals can be configured on the NetScaler MAS server.
- Analytics. By default, every minute, the decoder collects and decodes the data received from all managed NetScaler instances and writes it to the internal database. This polling interval is not configurable.
In addition to polling, events generated by managed NetScaler instances are received by NetScaler MAS through SNMP traps sent the instances. For example, an event is generated when there is a system failure or change in configuration.
During instance backup, SSL files, CA certificate files, NetScaler templates, database information, and so on are downloaded to NetScaler MAS. During a configuration audit, ns.conf files are downloaded and stored in the file system. All information collected from managed NetScaler instances are stored internally within the database.
When you add an instance to NetScaler MAS, it implicitly adds itself as a trap destination for the instance and collects inventory of the instance.
The following diagram describes how NetScaler MAS implicitly discovers and adds instances.
As shown in the diagram, the following steps are performed implicitly by NetScaler MAS.
1) NetScaler MAS sends an Internet Control Message Protocol (ICMP) ping to locate the instance. Then, it uses the instance profile details to log on to the instance. Using a NetScaler NITRO call, NetScaler MAS retrieves the license information of the instance. On the basis of the licensing information received, it determines whether the instance is a NetScaler instance and the type of NetScaler platform (for example, NetScaler MPX, NetScaler VPX, NetScaler SDX, or NetScaler Gateway). On succesful detection of the NetScaler instance, it is added to the NetScaler MAS internal database.
For NetScaler SD-WAN instances, NetScaler MAS does not detect the instance by using licensing information. Instead, after locating the instance by using ICMP ping, it sends a NITRO request to the instance to check for the instance type and version.
This step might fail if the instance profile does not include the correct credentials. For NetScaler MPX, VPX, SDX, and NetScaler Gateway instances, this step might also fail if the licenses are not applied to the instance.
2) NetScaler MAS adds its IP address to the list of trap destinations on the instance.This allows NetScaler MAS to receive traps generated on the NetScaler instance.
This step might fail if the number of trap destinations on the instance exceeds the maximum limit of trap destinations. The maximum limit on NetScaler instances is 20.
For SD-WAN instances, NetScaler MAS adds its IP address as the SNMP manager on the instance.
3) NetScaler MAS collects inventory from the instance by sending a NITRO request. It collects instance details such as host name, software version, running and saved configuration, certificate details, entities configured on the instance, and so on.
This step might fail because of network or firewall issues.
For more information about adding instances, see Adding an Instance to NetScaler MAS.