This repo is just here to share how to quickly perform a load test against a Varnish instance that is in front of a SPARQL endpoint.
Varnish is agnostic of the exact SPARQL queries used (once preloaded) and thus can be concluded that as long as similar queries and response sizes are given it is expected to behave similarly.
k6 run --vus 10 --duration 10s test.jsYou can adjust the number of virtual users and the duration of the test as needed.
The test will send a SPARQL query against the cached SPARQL endpoint, and check if the returned status code is 200. The first time it will be run, the amount of queries would be very low, as no queries are cached yet. Once you ensure that all queries are cached, the amount of queries will be higher, as the queries are cached.
Let's run the test with 100 virtual users for 10 seconds, after we ensured that all entries are cached:
k6 run --vus 100 --duration 10s test.jsHere are the results:
✓ is status 200
checks.........................: 100.00% ✓ 1151 ✗ 0
data_received..................: 512 MB 46 MB/s
data_sent......................: 12 MB 1.0 MB/s
http_req_blocked...............: avg=27.9ms min=0s med=0s max=369.58ms p(90)=1µs p(95)=314.53ms
http_req_connecting............: avg=8.64ms min=0s med=0s max=131.23ms p(90)=0s p(95)=95.78ms
http_req_duration..............: avg=889.8ms min=40.05ms med=141.77ms max=8.45s p(90)=2.39s p(95)=3.07s
{ expected_response:true }...: avg=889.8ms min=40.05ms med=141.77ms max=8.45s p(90)=2.39s p(95)=3.07s
http_req_failed................: 0.00% ✓ 0 ✗ 1151
http_req_receiving.............: avg=746.24ms min=12µs med=38.77ms max=8.33s p(90)=2.16s p(95)=2.85s
http_req_sending...............: avg=49.97µs min=17µs med=41µs max=1.71ms p(90)=75µs p(95)=88µs
http_req_tls_handshaking.......: avg=14.44ms min=0s med=0s max=192.45ms p(90)=0s p(95)=166.92ms
http_req_waiting...............: avg=143.51ms min=18.69ms med=119.08ms max=1.61s p(90)=231.14ms p(95)=313.16ms
http_reqs......................: 1151 103.417913/s
iteration_duration.............: avg=917.93ms min=97.78ms med=357ms max=8.45s p(90)=2.39s p(95)=3.07s
iterations.....................: 1151 103.417913/s
vus............................: 8 min=8 max=100
vus_max........................: 100 min=100 max=100
running (11.1s), 000/100 VUs, 1151 complete and 0 interrupted iterations
default ✓ [======================================] 100 VUs 10sThis means that the Varnish endpoint was able to handle aroud 100 requests per second, once entries are cached.
- Varnish, a caching solution
- varnish-post, used to cache POST requests
- clear-sparql-cache-endpoint, used to purge the cache for some particular Varnish tags, using a SPARQL query