testcaches

testcaches

The testcaches tool simulates multiple ATS caches' _astats endpoints.

Its primary goal is for testing the Monitor under load, but it may be useful for testing other components.

A list of parameters can be seen by running ./testcaches -h. There are only three: the first port to use, the number of ports to use, and the number of remaps (delivery services) to serve in each fake server.

Each port is a unique fake server, with distinct incrementing stats.

When run with no parameters, it defaults to ports 40000-40999 and 1000 remaps.

Stats are served at the regular ATS stats_over_http endpoint, _astats. For example, if it's serving on port 40000, it can be reached via curl http://localhost:40000/_astats. It also respects the ?application=system query parameter, and will serve only system stats (the Monitor "health check" [as opposed to the "stat check"]). For example, curl http://localhost:40000/_astats?application=system.

Commands

The testcaches app accepts a number of commands, which manipulate the data it serves. These command are all available via HTTP requests.

Each HTTP request is made to a fake cache at a specific port. Thus, you can modify data served by each fake cache independently.

The commands are:

/cmd/setstat

Sets how much a stat increments by every interval (currently, an interval is hard-coded to 1 second). Accepts a min and max, and will increment by a random number between them. The min may equal the max, if a constant increment is desired.

Query Parameters: remap - the remap rule to set stat - the stat to set min - the minimum number to increment by max - the minimum to increment by

Example: curl -Lvsk http://localhost:4242/cmd/setstat?remap=num1.example.net&stat=out_bytes&min=10&max=25

setsystem

Sets system stats to constant values. Multiple stats may be set with a single request.

Query Parameters: loadavg1m - the 1m loadavg in the system object. loadavg5m - the 5m loadavg in the system object. loadavg10m - the 10m loadavg in the system object. speed - the network interface speed in the system object. This number is in kilobits. I.e. 20000 means 20Gbps.

Example: curl -sk 'http://localhost:4242/cmd/setsystem?loadavg1m=10.1&loadavg5m=27.92&loadavg10m=3.4&speed=20000'

setdelay

Sets the delay for serving all _astats requests to this fake cache. Accepts a minimum and maximum, which may be qual, and delays the request by a random interval between them. When a delay is set, the server immediately accepts client requests, reads headers and sets up the connection, and then delays writing out the body.

Query Parameters: min - the minimum delay time, in milliseconds max - the maximum delay time, in milliseconds

Example: curl -Lvsk 'http://localhost:4242/cmd/setdelay?min=200&max=600'

Docker

Build environment variables: none

Run environment variables:

• NUM_PORTS - app numPorts argument
• NUM_REMAPS - app numRemaps argument
• PORT_START - app portStart argument