20 replies

Unexpected Execution Time with Parallel Requests and Database Transactions

Hi all, I'm new to Effect, and I have encountered quite weird behaviour. I have a fake long transactions, something like

select pg_sleep(5);

select pg_sleep(5);

three times, each time as a separate effect. I wrapped that into an API and execute 20 requests in parallel. When these three fake steps are wrapped into transaction then test takes 30 seconds (since there is max 10 connections to database it is expected). However, when I remove transaction it turns out that the first execution takes 1m 15 sec while the next ones takes 30 seconds. What happens here? Here is the code: https://gist.github.com/rpiotrow/97c7e2565782a211b917cd209a51f70b The result is below:

$ time seq 20 | xargs -n1 -P20 curl -X 'POST' http://localhost:3000/experiment/long-transactions --data

real    1m15,082s
user    0m0,108s
sys    0m0,070s

$ time seq 20 | xargs -n1 -P20 curl -X 'POST' http://localhost:3000/experiment/long-transactions --data

real    0m30,053s
user    0m0,087s
sys    0m0,097s

$ time seq 20 | xargs -n1 -P20 curl -X 'POST' http://localhost:3000/experiment/long-transactions --data

real    1m15,082s
user    0m0,108s
sys    0m0,070s

$ time seq 20 | xargs -n1 -P20 curl -X 'POST' http://localhost:3000/experiment/long-transactions --data

real    0m30,053s
user    0m0,087s
sys    0m0,097s

BTW, there is an (empty) PostgreSQL database running under the hood.

Effect Community•12mo ago•

20 replies

rpiotrow

Unexpected Execution Time with Parallel Requests and Database Transactions

Hi all, I'm new to Effect, and I have encountered quite weird behaviour. I have a fake long transactions, something like

select pg_sleep(5);

select pg_sleep(5);

$ time seq 20 | xargs -n1 -P20 curl -X 'POST' http://localhost:3000/experiment/long-transactions --data

real    1m15,082s
user    0m0,108s
sys    0m0,070s

$ time seq 20 | xargs -n1 -P20 curl -X 'POST' http://localhost:3000/experiment/long-transactions --data

real    0m30,053s
user    0m0,087s
sys    0m0,097s

$ time seq 20 | xargs -n1 -P20 curl -X 'POST' http://localhost:3000/experiment/long-transactions --data

real    1m15,082s
user    0m0,108s
sys    0m0,070s

$ time seq 20 | xargs -n1 -P20 curl -X 'POST' http://localhost:3000/experiment/long-transactions --data

real    0m30,053s
user    0m0,087s
sys    0m0,097s

BTW, there is an (empty) PostgreSQL database running under the hood.

Unexpected Execution Time with Parallel Requests and Database Transactions

Similar Threads

Unexpected Execution Time with Parallel Requests and Database Transactions

Similar Threads

Similar Threads

Similar Threads