.\" Generated by Mmark Markdown Processer - mmark.miek.nl
.TH "COREDNS-GRPC_SERVER" 7 "March 2026" "CoreDNS" "CoreDNS Plugins"

.SH "NAME"
.PP
\fIgrpc_server\fP - configures DNS-over-gRPC server options.

.SH "DESCRIPTION"
.PP
The \fIgrpc_server\fP plugin allows you to configure parameters for the DNS-over-gRPC server to fine-tune the security posture and performance of the server.

.PP
This plugin can only be used once per gRPC listener block.

.SH "SYNTAX"
.PP
.RS

.nf
grpc\_server {
    max\_streams POSITIVE\_INTEGER
    max\_connections POSITIVE\_INTEGER
}

.fi
.RE

.IP \(bu 4
\fB\fCmax_streams\fR limits the number of concurrent gRPC streams per connection. This helps prevent unbounded streams on a single connection, exhausting server resources. The default value is 256 if not specified. Set to 0 for unbounded.
.IP \(bu 4
\fB\fCmax_connections\fR limits the number of concurrent TCP connections to the gRPC server. The default value is 200 if not specified. Set to 0 for unbounded.


.SH "EXAMPLES"
.PP
Set custom limits for maximum streams and connections:

.PP
.RS

.nf
grpc://.:8053 {
    tls cert.pem key.pem
    grpc\_server {
        max\_streams 50
        max\_connections 100
    }
    whoami
}

.fi
.RE

.PP
Set values to 0 for unbounded, matching CoreDNS behaviour before v1.14.0:

.PP
.RS

.nf
grpc://.:8053 {
    tls cert.pem key.pem
    grpc\_server {
        max\_streams 0
        max\_connections 0
    }
    whoami
}

.fi
.RE