Accessing data using REST services
You can access z/OS® Data Gatherer
and Function Registry for z/OS
data by using REST calls via HTTP.
To use Data Gatherer REST services, you must set up a
separate z/OSMF managed Liberty server instance. 
SMF REST services
The SMF REST services provide access to SMF data via REST calls. As shown in Figure 1, SMF REST services run inside the separate z/OSMF managed Liberty server instance. SMF REST services provide several REST endpoints which can be called by client applications. SMF REST services invoke the z/OS Data Gatherer interface, GRBSMFR, to retrieve SMF data set metadata and SMF record data, depending on the request input. The application then processes the data into a JSON representation of the requested SMF data.
To retrieve SMF data on a call to SMF REST services, the caller's user ID must have authorization to access the SMF data.
Monitor II REST services
The Monitor II REST services provide access to IBM® Function Registry for z/OS data via REST calls. As shown in Figure 2, Monitor II REST services runs within the separate z/OSMF managed Liberty server instance. Monitor II REST services provide several REST endpoints which can be called by client applications. z/OS Data Gatherer Monitor II REST services read and retrieve data from the Function Registry for z/OS from any system in the sysplex that supports this function. The application then processes the data into a JSON representation of the requested function registry data.
To retrieve Monitor II data on a call to Monitor II REST services, the caller's user ID must have authorization to access the Monitor II data.
For an overview of IBM Function Registry for z/OS, see Using and registering functions with the IBM Function Registry for z/OS in z/OS MVS Programming: Authorized Assembler Services Guide.

Monitor III REST services
The Monitor III REST services provide access to Monitor III VSAM data sets or local in-storage buffer via REST calls. As shown in Figure x on page x, Monitor III REST services run within the separate z/OSMF managed Liberty server instance. Monitor III REST services provide several REST endpoints which can be called by client applications. z/OS Data Gatherer Monitor III REST services read and retrieve data from any system with an active Monitor III session (local in-storage buffer) or from existing Monitor III VSAM data sets. Data is retrieved by using sysplex data server, ERB3XDRS. The application returns the requested Monitor III data in a JSON representation.
Retrieval of Monitor III data by using Monitor III REST services only works if the caller's user ID has authorization to access Monitor III data. If Monitor III data is read from VSAM data sets, the caller's user ID must have the authorization to access Monitor III data and Monitor III VSAM data sets.
For an overview of the z/OS Data Gatherer Monitor III sysplex data retrieval service, ERB3XDRS, see ERB3XDRS — Monitor III sysplex data retrieval service in z/OS Data Gatherer Programmer's Guide.
