To begin the configuration, you must enable the HTTP/2 feature in the HTTP profile. If the client sends the HTTP 1.1 requests, the appliance bridges the request and forward it to the back-end server.

At the command prompt, type:

add ns httpProfile <name> - http2 ( ENABLED | DISABLED ) [-http2Direct ( ENABLED | DISABLED )]

Example:

add ns httpProfile http2gRPC -http2Direct ENABLED -http2 ENABLED

To enable the HTTP/2 support globally on the server side by using the NetScaler command line.

At the command prompt, type:

set ns httpParam -http2ServerSide( ON | OFF )

Example:

set ns httpParam -http2ServerSide ON

To add a load balancing virtual server by using the NetScaler command interface

At the command prompt, type:

add lb vserver <name> <service type> [(<IP address>@ <port>)] [-httpProfileName <string>]

Example:

add lb vserver lb-grpc HTTP 10.10.10.10 80 -httpProfileName http2gRPC

To add a gRPC service with the HTTP profile by using the NetScaler command interface.

At the command prompt, type:

add service <name> (<IP> | <serverName> ) <serviceType> <port> [-httpProfileName <string>]

Example:

add service svc-grpc 10.10.10.10 HTTP 80 -httpProfileName http2gRPC

To bind a gRPC end point service to the load balancing virtual server by using the CLI.

At the command interface, type:

bind lb vserver <name> <serviceName>

Example:

bind lb vserver lb-grpc svc-grpc

In gRPC bridging scenario, the gRPC service responds to the request with a gRPC status-code. The appliance maps the gRPC status code to a corresponding HTTP response code and reason phrase. The mapping is done based on the table provided below. The NetScaler appliance when sending the HTTP/1.1 response to the client sends the HTTP status code and the reason phrase.

The NetScaler appliance buffers the gRPC response from the back-end server until the response trailer is received. This breaks bi-directional gRPC calls. Also, if the gRPC response is huge, it consumes a significant amount of memory to buffer the response completely. To resolve the issue, the gRPC bridging configuration is enhanced to limit buffering by time and/or size. If the buffer size or time limit exceeds threshold, the appliance stops buffering and forwards the response to the client even when any one of the limitations triggers (either the trailer is not received within the configured buffer size or if the configured timeout occurs). As a result, the configured policies and its expressions (based on grpc-status code) do not work as expected.

To limit gRPC buffering by time and/or size by the CLI, you can configure when you add a new HTTP profile or configure when you modify an existing profile.

At the command prompt, type:

add ns httpProfile http2gRPC [-grpcHoldLimit <positive_integer>] [-grpcHoldTimeout <positive_integer>]

Or

set ns httpProfile http2gRPC [-grpcHoldLimit <positive_integer>] [-grpcHoldTimeout <positive_integer>]

Where,

grpcholdlimit. Maximum size in bytes allowed to buffer gRPC packets until trailer is received. You can configure both the parameters and any one.

Default value: 131072 Minimum value: 0 Maximum value: 33554432

grpcholdtimeout. Maximum time in milliseconds allowed to buffer gRPC packets until trailer is received. The value should be in multiples of 100. Default value: 1000 Minimum value: 0 Maximum value: 180000

Example:

add httpprofile http2gRPC -grpcholdlimit 1048576 -grpcholdtimeout 5000 set httpprofile http2gRPC -grpcholdlimit 1048576 -grpcholdtimeout 5000

For detail GUI procedures for binding service and load balancing virtual servers, see Load Balancing topic.