nailgun

nailgun is a DNS performance testing client written in Rust using trust-dns-proto and tokio. Open to PRs, issues, comments!

nailgun is written as a hobby project first and foremost, it's inspired by flamethrower and copies some of its arguments. It is single-threaded by default but configurable to use many threads. You can specify both the number of traffic generators (with tcount) and the number of tokio worker threads (with wcount), nailgun will start tcount * wcount generators. Most of the time, this is not necessary as 1 concurrent generator and a single worker thread is more than enough. Testing against a local dnsdist instance configured to return instantly with NXDOMAIN, (yes, not a real-world benchmark) nailgun can do well over 250K QPS (1 worker thread & generator).

nailgun uses tracing for logging so RUST_LOG can be used in order to control the logging output.

Features

Rate limiting

You can specify a specific QPS with -Q, this allows you to set a desired QPS rate which will be divided up over all the senders.

Output

--output allows you to specify different logging formats, courtesy of tracing. "pretty", "json" and "debug" are currently supported with "pretty" as the default. You can use RUST_LOG to filter on the output (ex. RUST_LOG="naildns=trace" will print trace level from the naildns bin only). nailgun uses stdout by default, but will log to file if you accompany this with the -o flag and a path.

Regardless of these options, a summary is printed to stdout sans-tracing after the run is over.

Generators

There are multiple generator types available with -g, the default is static but you can generate queries from file also or with some portion randomly generated.

DoH (new!)

nailgun can now send DoH messages!

naildns dns.google -Q 2 -P doh

Usage

naildns --help

By default, nailgun will spawn a single threaded tokio runtime and 1 traffic generator:

naildns 0.0.0.0 -p 1953

This can be scaled up:

naildns 0.0.0.0 -p 1953 -w 16 -t 1

Will spawn 16 OS threads (w/wcount) on the tokio runtime and 1 traffic generator (t/tcount) per thread spawned, for a total of 16*1 = 16 traffic generators.

Note If you want a quick server to test against, I've been spinning up dnsdist and adding addAction(AllRule(), RCodeAction(3)) to its config so that all DNS messages immediately return with NXDomain.

Building & Installing

To build locally:

cargo build --release

naildns binary will be present in target/release/naildns

From crates.io

Local

To install locally

cargo install

TODO

• throttle based on # of timeouts
• first batch of messages always seems to be double the set QPS (try --limit-secs 5 -Q 10 for example, it will end up sending 60 queries)
• some TODO cleanups left in the code to address
• arg parsing for generator is very different from flamethrower because clap doesn't seem to support parsing it in the same style-- would be nice to figure this out
• combine logging output from all generators rather than having them run individually
• more generator types?
• maybe leverage other parts of trustdns to make options for interesting types of queries. DOT? DOH?
• suggestions? bugs?