Nicstat is a powerful tool for monitoring network IO
1. View network card information
2. Check the network card interval 2 seconds, 2 times
- Time column: Represents the response times for the current sample.
- Lo and eth0: the NIC name.
- RKB/S: The number of kilobytes per second received.
- WKB/S: The number of kilobytes written per second.
- RPK/S: The number of packets received per second.
- WPK/S: The number of packets written per second.
- Ravs: The average size of packets received.
- WAvs: The average size of the transmitted packets.
- %util: Network card Utilization (percentage).
- Sat: The number of errors per second of the NIC. The NIC is close to a full indicator. When trying to diagnose network problems, it is recommended to use the-X option to view more statistics.
3. View TCP and UDP-related
Detailed TCP Output
- INKB: Represents the kilobytes received per second.
- OUTKB: Represents the kilobytes transmitted per second.
- INSEG: Represents the TCP data segment (TCP segments) received per second.
- OUTSEG: Represents the TCP data segment (TCP segments) transmitted per second.
- Reset: Indicates the number of times a TCP connection has transitioned from a established or close-wait state directly to a closed state.
- Attf: Represents the number of times a TCP connection transitions from a syn-sent or SYN-RCVD state directly to a closed state, plus the number of times a TCP connection transitions from SYN-RCVD state directly to listen state
- %retx: Represents the percentage of TCP data segment (TCP segments) retransmission. That is, the transmitted TCP data segment contains one or more eight-bit bytes that were previously transmitted.
- Inconn: Indicates the number of times a TCP connection has transitioned from a listen state directly to a SYN-RCVD state.
- Outcon: Indicates the number of times a TCP connection has transitioned from a closed state directly to a syn-sent state.
- Drops: Represents the number of connections dropped from the queue that completed the connection (completed connection) and the queue for an incomplete connection (incomplete connection).
UDP output Detailed
- INDG: UDP datagram received per second (UDP datagrams)
- OUTDG: UDP Datagram transmitted per second (UDP datagrams)
- Inerr: Packets received that cannot be processed due to an error
- Outerr: Packets that cannot be successfully transmitted due to errors
4. In megabytes
Reference:
http://www.zrwm.com/?p=7235
Mans Nicstat
Java Performance optimization
Operating system performance Monitoring-Network IO
