more aggressively. Let me to remind again: each orphan eats
up to ~64K of unswappable memory.
-tcp_max_ssthresh - INTEGER
- Limited Slow-Start for TCP with large congestion windows (cwnd) defined in
- RFC3742. Limited slow-start is a mechanism to limit growth of the cwnd
- on the region where cwnd is larger than tcp_max_ssthresh. TCP increases cwnd
- by at most tcp_max_ssthresh segments, and by at least tcp_max_ssthresh/2
- segments per RTT when the cwnd is above tcp_max_ssthresh.
- If TCP connection increased cwnd to thousands (or tens of thousands) segments,
- and thousands of packets were being dropped during slow-start, you can set
- tcp_max_ssthresh to improve performance for new TCP connection.
- Default: 0 (off)
-
tcp_max_syn_backlog - INTEGER
Maximal number of remembered connection requests, which have not
received an acknowledgment from connecting client.
connect() to perform a TCP handshake automatically.
The values (bitmap) are
- 1: Enables sending data in the opening SYN on the client.
+ 1: Enables sending data in the opening SYN on the client w/ MSG_FASTOPEN.
2: Enables TCP Fast Open on the server side, i.e., allowing data in
a SYN packet to be accepted and passed to the application before
3-way hand shake finishes.
different ways of setting max_qlen without the TCP_FASTOPEN socket
option.
- Default: 0
+ Default: 1
Note that the client & server side Fast Open flags (1 and 2
respectively) must be also enabled before the rest of flags can take
typical pfifo_fast qdiscs.
tcp_limit_output_bytes limits the number of bytes on qdisc
or device to reduce artificial RTT/cwnd and reduce bufferbloat.
- Note: For GSO/TSO enabled flows, we try to have at least two
- packets in flight. Reducing tcp_limit_output_bytes might also
- reduce the size of individual GSO packet (64KB being the max)
Default: 131072
tcp_challenge_ack_limit - INTEGER