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Weekly Report -- 08/08/2014




Added support for the new amp-tcpping test to ampy and amp-web.

Started on yet another major database schema change. This time, we're getting rid of address-based streams for amp collections and instead having one stream per address family per target. For example, instead of having an amp-icmp stream for every google address we observed, we'll just have two: one for ipv4 and one for ipv6.

This will hopefully result in some performance improvements. Firstly, we'll be doing a maximum of 2 inserts per test/source/dest combination, rather than anywhere up to 20 for some targets. We'll also have a lot less streams to search and process when starting up a NNTSC client. Finally, we should save a lot of time when querying for data, as almost all of our use cases were taking the old stream data and aggregating it based on address family anyway. Now our data is effectively pre-aggregated -- we also will have a lot less joins and unions across multiple tables.

By the end of the week, my test NNTSC was successfully collecting and storing data using this new schema. I also had ampy fetching data for amp-icmp and amp-tcpping, with amp-traceroute most of the way towards working. The main complexity with amp-traceroute is that we should be deploying Brendon's AS path traceroute next week, so I'm changing the rainbow graph to fetch AS path data and adding a method to query the IP path data that will support the monitor map graph that was implemented last summer.

Spent a day working on libtrace following some bug reports from Mike Schiffman at Farsight Security. Fixed some tricky bugs that popped up when using BPF filters with the event API.

Deployed the update-less version of NNTSC on skeptic finally. Unfortunately this initially made the performance even worse, as we were trying to keep the last timestamp cache up to date after every message. Changed it so that NNTSC only writes to the cache once every 5 mins of realtime, which seems to have solved the problem. In fact, we are now finally starting to (slowly) catch up on the message queue on skeptic.