Request Counter

Request Counter application - Go HTTP server that on each request responds with a counter of the total number of requests that it has received during the last time period (could be configurable). Request Counter can store it's data in memory only or persist it to a file.

Request Counter stores counts into intervals (buckets). Each of them represent particular time interval.

Intervals are sored in a ring.

First two uint64 values in data are metainfo:

• Current position in the ring
• Time of first access of interval on current position

HTTP interface

To get request count execute next curl command:

curl http://localhost:8080/requestcount

GET /requestcount return json:

{
    "count":3
}

Installation

To install Request Counter application glide (https://github.com/Masterminds/glide) package manager must be installed.

To build Request Counter you can just execute:

make

To run tests:

make test

To run the application:

./requestcounter -config config-file.yaml

Configuration

# address to listen on
host: 0.0.0.0

# port to listen on
port: 8080

# logging lever, could be: error, warning, info, debug
log-level: error

# count of intervals (buckets)
interval-count: 100

# duration of each interval 
interval-duration: 600ms

# persist data to a file or store in memory
persistent: true

# file name where data will be persisted
filename: /tmp/reqcnt.dat

# flush data to a file time interval
persist-duration: 5s

See example-config.yaml.

Limitations

• Request Counter would not return correct values if config values interval-count or interval-duration were changed before restart.

TODO

• Add more unit and functional tests