ouroboros/src/lib/config.h.in, branch 0.21.2

lib: Revise app flow allocation

2024-02-23T15:41:37Z

This revises the application flow allocator to use the flow_info struct/message between the components. Revises the messaging to move the use protocol buffers to its own source (serdes-irm). Adds a timeout to the IRMd flow allocator to make sure flow allocations don't hang forever (this was previously taken care of by the sanitize thread). Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update licenses to 2024

2024-01-13T09:20:14Z

Slow but steady. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update copyright to 2023

2023-02-13T20:10:10Z

2022 was a rather slow year... Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Fix RTO update on timeout

2022-04-03T16:01:02Z

This fixes the RTO doubling on timeout according to Karn/Partridge. Exponentially increasing RTO when it times out (e.g. doubling) fixes the problem that a sudden increase in real RTT starves the sRTT updates by never getting out of backoff as retransmitted packets can't update RTT. Added an parameter to make it less aggressive, default is doubling. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update copyright to 2022

2022-04-03T16:01:02Z

Growing pains. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Add support for Linux RTT estimator

2022-04-03T16:01:01Z

This adds the option to use the Round-Trip-Time (RTT) estimation algorithm as it is implemented in the TCP implementation in Linux. It looks like it outperforms the TCP default algorithm, so I enabled this one by default. Also adds the option to change the RTO timeout calculation to include more (or less) than 4 times the mdev (specified as a power of 2. Left the default value to 2 (so, 4 mdevs), but 3 (8 mdevs) gives better results in my tests. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Non-configurable delayed acks in FRCP

2022-03-30T12:55:13Z

It doesn't really make sense to manually and one-sidedly configure the timeout of delayed acknowledgements, as setting it too high upsets the peer's sRTT estimates. Even worse, it also causes a lot of spurious retransmissions if it exceeds the sRTT mean deviation calculated by the receiver. Compensating on bare acknowledgment for the ack delay could improve the RTT estimate deviation, but not the spurious retransmissions if it was set too high. This sets the delayed ack to wait for a single RTT mean deviation. Probably needs more tweaking to further reduce differences between the RTT estimates at the sender and receiver, e.g. compensate the RTT estimate for delayed acks, or increase the RTO to add 8 mdevs to sRTT instead of 4. However, it looks like the mdev estimate is the trickiest one to get to sync, not the RTT average. Linux reduces the sample weight for mdev from 1/4 to 1/32 in some cases, will give that a shot some day too to see if that further align sRTT estimates. In any case, this patch already improves things a lot. Also fixes a bug where the sender was sending acknowlegments on the first packets in flight for the 0 sequence number. The receiver activity was measured in seconds but compared to a timeout value in nanoseconds. There's still a lot of spurious retransmissions that start after actual packet loss occurs, I'm still investigating what causes it. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Fix buffer allocation when retransmitting

2022-03-11T16:51:27Z

The timerwheel was retransmitting packets and the error check for negative values of the rbuff allocation was instead checking for non-zero values, causing a buffer allocation to succeed but the program to continue down the unhappy path leaving that packet stuck in the buffer unattended. Also fixes wrongly scheduled retransmissions that cause packet storms. FRCP is much more stable now. Still needs some work for high bandwidth-delay products (fast-retransmit). Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

lib: Application RIB with FRCT statistics

2021-06-30T07:20:15Z

Application flows can now be monitored from the RIB, exposing FRCT statistics (window edges, retransmission timeout, rtt estimate, etc). Application RIB requires user permissions to be able to access /dev/fuse. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders

build: Update email addresses

2021-01-03T10:57:05Z

The ugent email addresses are shut down, updated to Ouroboros mail addresses. Signed-off-by: Dimitri Staessens Signed-off-by: Sander Vrijders