Since yesterday, June 4
our service using bigquery randomly get a lot of timeout error.
the service has a cron job to run MERGE and DELETE sql to bigquery table, the sql utilize js udf not sure if it is related.
we using bigquery on demand.
same requests that can complete within 10s now hang and failing because hitting the 10 mins timeout i configured.
i am quite sure our query workload should be similar as the days before this problem.
u can see the slot estimator has a sudden spike since yesterday.
i think those hanging query just occupied all the slots.
i tried to get the timeout sql from job history,
reexecute it manually in google bigquery console,
some time it hang, and sometime it completed within 10s.
anyone else facing similar issue?
Since 2026-06-04, BigQuery on-demand queries in asia-southeast1 show severe regression for my MERGE jobs
By comparing June 3 and 4 for my table_1 and table_2, the workload did not increase, it decreased because it was interrupted by the timeout error:
- table_1 processed data decreased from 3388 GiB to 2219 GiB
- table_2 processed data decreased from 1173 GiB to 682 GiB
But slot efficiency degraded heavily:
- table_1 slot-min/GiB increased from 2.49 to 10.60
- table_2 slot-min/GiB increased from 1.35 to 24.95
p95 elapsed reached 631–1225 seconds, causing production app timeout at 10 minutes.
Manual reruns of the same SQL sometimes complete quickly and sometimes hang.
Queries use JavaScript UDF and MERGE into BigQuery tables.
I switch to use reservation slots, standard 1600 max slots.
now all timeout error disappear.
so i suspect these 2 days are in a condition that bigquery cant allocate 2000 soft cap slots to my project.
then the problem now is that are there a way to check how many slots i can get for on-demand, now i dont have that visibility at all.
