FAQ
Smarter by Design.Simpler for Business
TR7Enterprise Application Delivery & Security Platform

English

Türkçe

English

Türkçe

Appearance

Advanced

What is gRPC? ​

Short answer

gRPC is an RPC framework used for communication between services; it runs over HTTP/2 and encodes messages in binary form with Protocol Buffers (protobuf). The client calls a method in another service as if it were calling a local function; besides a single request-response, it also supports streams from the client, from the server or in both directions. Since it cannot fall back to HTTP/1.1, in TR7 HTTP/2 is required on both sides of the connection: on the HTTP vService, HTTP/2 is selected as the Frontend Protocol, and on the Backend Service, SSL Service is turned on and HTTP 2.0 enabled is selected in the ALPN field, or, for a gRPC server listening on unencrypted HTTP/2 (h2c), SSL Service is left off and Cleartext HTTP/2 (h2c) is checked; the connection that TR7 opens to the Backend Service is HTTP/1.1 by default. If TLS is to be terminated on the gRPC server, passthrough is used with an L7 TCP vService.

Where It Is Used in TR7 ​

WhereField / labelWhat for
Load Balancer → Load Balancer vService List → HTTP vService form → FrontendProtocol → Encrypted (HTTPS) → HTTP/2HTTP/2 on the client side
Load Balancer → Backend Services → Backend Service formSSL Service, ALPN → HTTP 2.0 enabled (default HTTP 2.0 disabled)HTTP/2 over TLS on the Backend Service side
Load Balancer → Backend Services → Backend Service formCleartext HTTP/2 (h2c) (default off; not displayed while SSL Service is checked)HTTP/2 without TLS on the Backend Service side
Load Balancer → Load Balancer vService List → L7 TCP vService form → FrontendProtocol → TCPPassing the traffic to the gRPC server without decrypting the TLS (passthrough)

Step-by-step configuration and verification of both methods: Can I put my gRPC services behind TR7?

Common Misconceptions ​

  • "Making the frontend HTTP/2 is enough." The connection that TR7 opens to the Backend Service is HTTP/1.1 by default; if HTTP 2.0 enabled is not selected in the ALPN field or, for an unencrypted server, Cleartext HTTP/2 (h2c) is not checked, gRPC calls fail.
  • "TR7 establishes HTTP/2 to the Backend Service only over TLS." If Cleartext HTTP/2 (h2c) is checked on the Backend Service, TR7 connects to the gRPC server listening on unencrypted HTTP/2 with HTTP/2 without TLS; this setting is effective only on HTTP vServices and while SSL Service is off.
  • "There is a health check type specific to gRPC." There is no gRPC among the health check types; the TCP type, which tests the connection, or the TCPS type, which also tests the TLS handshake, is used.
  • "The Keep header names action can be used together with gRPC." On a vService that Keep Header Names is bound to, HTTP/2 is turned off and gRPC does not work.

How it is done in the documentation

Related questions