Observability User Guide

A host refers to the endpoint, such as a server or client, that serves as the reference point for analysis. It clarifies the direction in which a specific metric is observed. Every connection goes from the host to the peer. Terminologies like Transmit (Tx), Receive (Rx), outbound, and inbound are always interpreted from the host's perspective. For instance, an outbound connection refers to the host sending data, while an inbound connection means the host is receiving data.

Server latency is the round-trip time between the client sending a TCP packet and the server acknowledging the packet, as observed by the monitoring point.

Peer client latency is the round trip time between the server sending a TCP packet and the client acknowledging the packet as observed by the monitoring point.

Network latency is the response time as measured between the client’s initial connection request (SYN packet) and the server’s response (SYN-ACK packet), as observed by the monitoring point.

Client latency is the round-trip time between the server sending a TCP packet and the client acknowledging the packet as observed by the monitoring point.

Peer server latency is the round-trip time between the client sending a TCP packet and the peer server acknowledging the packet as observed by the monitoring point.

Peer network latency is the response time as measured between the client’s initial connection request (SYN packet) and the peer server’s response (SYN-ACK packet) as observed by the monitoring point.

The percentage of inbound connection attempts that failed to complete a three-way TCP handshake (SYN-SYNACK-ACK) where the host is a server.

The percentage of outbound connection attempts that failed to complete a three-way TCP handshake (SYN-SYNACK-ACK) where the host is a client.

The total number of SYN packets received for the specific endpoint or application where the host is a server.

The total number of SYN-ACK packets transmitted for the specific endpoint or application where the host is a server.

The number of attempted connections to the endpoint that failed to complete the three-way TCP handshake (SYN-SYNACK-ACK).

The number of SYNACK packets received by the endpoint where the corresponding initial SYN packet is missing or not detected.

A session where the host, acting as a server, does not successfully receive any data. A connection was established, but no data transfer occurred during the session.

The total number of SYN packets transmitted for the specific endpoint or application where the host is a client.

The total number of SYN-ACK packets received for the specific endpoint or application where the host is a client.

The number of connections the endpoint attempted to establish that failed to complete the three-way TCP handshake (SYN-SYNACK-ACK).

The number of SYN packets transmitted by the endpoint where the corresponding SYNACK packet is not received.

A session where the host, acting as a client, does not successfully transmit any data. A connection was established, but no data transfer occurred during the session.

The total number of packets transmitted with a lower than expected sequence number, indicating the packet is a retransmission of a previously sent packet.

The number of missing packets with gaps in the TCP sequence numbers that are observed between two consecutive packets transmitted by an endpoint.

The number of packets transmitted by an endpoint with the same sequence number as a previously transmitted packet.

The number of reset (RST) packets transmitted for the specific endpoint or application.

The number of TCP packets the host has transmitted with a window size of zero. This indicates the host has reached its maximum capacity and cannot process more incoming data. This is a signal for the peer to pause or stop sending data until the host has sufficient memory or resources to process the incoming data.

The total number of packets received with a lower than expected sequence number, indicating the packet is a retransmission of a previously sent packet.

The number of missing packets with gaps in the TCP sequence numbers that are observed between two consecutive packets received by an endpoint.

The number of packets received by an endpoint with the same sequence number as a previously received packet.

The number of reset (RST) packets received for the specific endpoint or application.

The number of TCP packets the host has received with a window size of zero from the peer. This indicates that the peer has reached its maximum capacity and cannot process more incoming data. This is a signal for the host to pause or stop sending data until the peer has sufficient memory or resources to process the incoming data.

The maximum number of TCP sessions that are currently open where the host is a server.

The maximum number of received flows by a host as observed by a monitoring point.

The total number of inbound connections that have successfully completed a three-way TCP handshake (SYN-SYNACK-ACK) where the host is a server.

The maximum number of TCP sessions that are currently open where the host is a client.

The maximum number of transmitted flows by a host as observed by a monitoring point.

The total number of outbound connections that have successfully completed a three-way TCP handshake (SYN-SYNACK-ACK) where the host is a client.

The total data in bits per second received by the endpoint or application calculated over the resolution of the dashboard.

The total number of bytes an endpoint or application received.

The total number of packets an endpoint or application received.

The total data in bits per second transmitted by the endpoint or application calculated over the resolution of the dashboard.

The total number of bytes an endpoint or application transmitted.

The total number of packets an endpoint or application transmitted.