=encoding utf-8 =head1 NAME ngx_stream_limit_conn_module - Module ngx_stream_limit_conn_module =head1 The C module (1.9.3) is used to limit the number of connections per the defined key, in particular, the number of connections from a single IP address. =head1 Example Configuration stream { limit_conn_zone $binary_remote_addr zone=addr:10m; ... server { ... limit_conn addr 1; limit_conn_log_level error; } } =head1 Directives =head2 limit_conn B limit_conn I> I>> B I B I Sets the shared memory zone and the maximum allowed number of connections for a given key value. When this limit is exceeded, the server will close the connection. For example, the directives limit_conn_zone $binary_remote_addr zone=addr:10m; server { ... limit_conn addr 1; } allow only one connection per an IP address at a time. When several C directives are specified, any configured limit will apply. The directives are inherited from the previous level if and only if there are no C directives on the current level. =head2 limit_conn_log_level B limit_conn_log_level I< C E C E C E C> B I B I B I Sets the desired logging level for cases when the server limits the number of connections. =head2 limit_conn_zone B limit_conn_zone I< I> C=I>:I>> B I Sets parameters for a shared memory zone that will keep states for various keys. In particular, the state includes the current number of connections. The I> can contain text, variables, and their combinations (1.11.2). Connections with an empty key value are not accounted. Usage example: limit_conn_zone $binary_remote_addr zone=addr:10m; Here, the key is a client IP address set by the C<$binary_remote_addr> variable. The size of C<$binary_remote_addr> is 4 bytes for IPv4 addresses or 16 bytes for IPv6 addresses. The stored state always occupies 32 or 64 bytes on 32-bit platforms and 64 bytes on 64-bit platforms. One megabyte zone can keep about 32 thousand 32-byte states or about 16 thousand 64-byte states. If the zone storage is exhausted, the server will close the connection.