docs: remove references to dead metric tcp_connection_duration_ms

This metric was dropped in linkerd/linkerd2-proxy#930

linkerd.io/content/2-edge/reference/proxy-metrics.md

@@ -192,8 +192,6 @@ layer.
   updated when the connection closes.
 * `tcp_read_bytes_total`: A counter of the total number of received bytes. This
   is updated when the connection closes.
-* `tcp_connection_duration_ms`: A histogram of the duration of the lifetime of a
-  connection, in milliseconds. This is updated when the connection closes.
 * `inbound_tcp_errors_total`: A counter of the total number of inbound TCP
   connections that could not be processed due to a proxy error.
 * `outbound_tcp_errors_total`: A counter of the total number of outbound TCP
@@ -220,7 +218,7 @@ are also added to transport-level metrics, when applicable.
 #### Connection Close Labels
 
 The following labels are added only to metrics which are updated when a
-connection closes (`tcp_close_total` and `tcp_connection_duration_ms`):
+connection closes (`tcp_close_total`):
 
 * `classification`: `success` if the connection terminated cleanly, `failure` if
   the connection closed due to a connection failure.

linkerd.io/content/2.11/reference/proxy-metrics.md

@@ -164,8 +164,6 @@ layer.
   updated when the connection closes.
 * `tcp_read_bytes_total`: A counter of the total number of received bytes. This
   is updated when the connection closes.
-* `tcp_connection_duration_ms`: A histogram of the duration of the lifetime of a
-  connection, in milliseconds. This is updated when the connection closes.
 
 ### Labels
 
@@ -184,7 +182,7 @@ are also added to transport-level metrics, when applicable.
 #### Connection Close Labels
 
 The following labels are added only to metrics which are updated when a
-connection closes (`tcp_close_total` and `tcp_connection_duration_ms`):
+connection closes (`tcp_close_total`):
 
 * `classification`: `success` if the connection terminated cleanly, `failure` if
   the connection closed due to a connection failure.

linkerd.io/content/2.12/reference/proxy-metrics.md

@@ -192,8 +192,6 @@ layer.
   updated when the connection closes.
 * `tcp_read_bytes_total`: A counter of the total number of received bytes. This
   is updated when the connection closes.
-* `tcp_connection_duration_ms`: A histogram of the duration of the lifetime of a
-  connection, in milliseconds. This is updated when the connection closes.
 * `inbound_tcp_errors_total`: A counter of the total number of inbound TCP
   connections that could not be processed due to a proxy error.
 * `outbound_tcp_errors_total`: A counter of the total number of outbound TCP
@@ -220,7 +218,7 @@ are also added to transport-level metrics, when applicable.
 #### Connection Close Labels
 
 The following labels are added only to metrics which are updated when a
-connection closes (`tcp_close_total` and `tcp_connection_duration_ms`):
+connection closes (`tcp_close_total`):
 
 * `classification`: `success` if the connection terminated cleanly, `failure` if
   the connection closed due to a connection failure.

linkerd.io/content/2.13/reference/proxy-metrics.md

@@ -192,8 +192,6 @@ layer.
   updated when the connection closes.
 * `tcp_read_bytes_total`: A counter of the total number of received bytes. This
   is updated when the connection closes.
-* `tcp_connection_duration_ms`: A histogram of the duration of the lifetime of a
-  connection, in milliseconds. This is updated when the connection closes.
 * `inbound_tcp_errors_total`: A counter of the total number of inbound TCP
   connections that could not be processed due to a proxy error.
 * `outbound_tcp_errors_total`: A counter of the total number of outbound TCP
@@ -220,7 +218,7 @@ are also added to transport-level metrics, when applicable.
 #### Connection Close Labels
 
 The following labels are added only to metrics which are updated when a
-connection closes (`tcp_close_total` and `tcp_connection_duration_ms`):
+connection closes (`tcp_close_total`):
 
 * `classification`: `success` if the connection terminated cleanly, `failure` if
   the connection closed due to a connection failure.

linkerd.io/content/2.14/reference/proxy-metrics.md

@@ -192,8 +192,6 @@ layer.
   updated when the connection closes.
 * `tcp_read_bytes_total`: A counter of the total number of received bytes. This
   is updated when the connection closes.
-* `tcp_connection_duration_ms`: A histogram of the duration of the lifetime of a
-  connection, in milliseconds. This is updated when the connection closes.
 * `inbound_tcp_errors_total`: A counter of the total number of inbound TCP
   connections that could not be processed due to a proxy error.
 * `outbound_tcp_errors_total`: A counter of the total number of outbound TCP
@@ -220,7 +218,7 @@ are also added to transport-level metrics, when applicable.
 #### Connection Close Labels
 
 The following labels are added only to metrics which are updated when a
-connection closes (`tcp_close_total` and `tcp_connection_duration_ms`):
+connection closes (`tcp_close_total`):
 
 * `classification`: `success` if the connection terminated cleanly, `failure` if
   the connection closed due to a connection failure.

linkerd.io/content/2.15/reference/proxy-metrics.md

@@ -192,8 +192,6 @@ layer.
   updated when the connection closes.
 * `tcp_read_bytes_total`: A counter of the total number of received bytes. This
   is updated when the connection closes.
-* `tcp_connection_duration_ms`: A histogram of the duration of the lifetime of a
-  connection, in milliseconds. This is updated when the connection closes.
 * `inbound_tcp_errors_total`: A counter of the total number of inbound TCP
   connections that could not be processed due to a proxy error.
 * `outbound_tcp_errors_total`: A counter of the total number of outbound TCP
@@ -220,7 +218,7 @@ are also added to transport-level metrics, when applicable.
 #### Connection Close Labels
 
 The following labels are added only to metrics which are updated when a
-connection closes (`tcp_close_total` and `tcp_connection_duration_ms`):
+connection closes (`tcp_close_total`):
 
 * `classification`: `success` if the connection terminated cleanly, `failure` if
   the connection closed due to a connection failure.

linkerd.io/content/2.16/reference/proxy-metrics.md

@@ -192,8 +192,6 @@ layer.
   updated when the connection closes.
 * `tcp_read_bytes_total`: A counter of the total number of received bytes. This
   is updated when the connection closes.
-* `tcp_connection_duration_ms`: A histogram of the duration of the lifetime of a
-  connection, in milliseconds. This is updated when the connection closes.
 * `inbound_tcp_errors_total`: A counter of the total number of inbound TCP
   connections that could not be processed due to a proxy error.
 * `outbound_tcp_errors_total`: A counter of the total number of outbound TCP
@@ -220,7 +218,7 @@ are also added to transport-level metrics, when applicable.
 #### Connection Close Labels
 
 The following labels are added only to metrics which are updated when a
-connection closes (`tcp_close_total` and `tcp_connection_duration_ms`):
+connection closes (`tcp_close_total`):
 
 * `classification`: `success` if the connection terminated cleanly, `failure` if
   the connection closed due to a connection failure.

linkerd.io/content/2.17/reference/proxy-metrics.md

@@ -192,8 +192,6 @@ layer.
   updated when the connection closes.
 * `tcp_read_bytes_total`: A counter of the total number of received bytes. This
   is updated when the connection closes.
-* `tcp_connection_duration_ms`: A histogram of the duration of the lifetime of a
-  connection, in milliseconds. This is updated when the connection closes.
 * `inbound_tcp_errors_total`: A counter of the total number of inbound TCP
   connections that could not be processed due to a proxy error.
 * `outbound_tcp_errors_total`: A counter of the total number of outbound TCP
@@ -220,7 +218,7 @@ are also added to transport-level metrics, when applicable.
 #### Connection Close Labels
 
 The following labels are added only to metrics which are updated when a
-connection closes (`tcp_close_total` and `tcp_connection_duration_ms`):
+connection closes (`tcp_close_total`):
 
 * `classification`: `success` if the connection terminated cleanly, `failure` if
   the connection closed due to a connection failure.