Slave scripts and jobs are scripts to me I generate on the fly to hard code the DB name so locking and optimzing know what they deal with.

Some of the code I'm working with right now (now including an error so this kind of lock up does not happen:

declare %private function wde:eval($query as xs:string, $bindings as map(*)?, $jobName as xs:string, $dontCheckQuery as xs:boolean) as item()* {
let $too-many-jobs := if (count(jobs:list()) >= xs:integer(db:system()//parallel)) then
error(xs:QName('wde:too-many-parallel-requests'), 'Too many parallel requests!') else (),
$query-is-sane := $dontCheckQuery or wde:query-is-sane($query),
$j := jobs:eval($query, $bindings, map {
'cache': true(),
'id': 'wde:'||$jobName||'-'||jobs:current(),
'base-uri': $wde:basePath||'/wde_'||$jobName||'.xq'}), $_ := jobs:wait($j)
return jobs:result($j)
};

declare
%rest:path("wde/{$dict}/{$index}")
%rest:query-param("q", "{$q}")
%rest:query-param("type", "{$type}")
%rest:GET
function wde:query-index($dict as xs:string, $index as xs:string, $q as xs:string*, $type as xs:string*) {
let $query-index-script := ``[
import module namespace wde = "http://acdh.oeaw.ac.at/wde" at 'rest.xqm';
declare variable $q external;
declare variable $index external;
declare variable $type external;
wde:do-query-index(collection("`{$dict}`"), $index, $q, $type)
]``
return wde:eval($query-index-script, map {
'q': $q,
'index': $index,
'type': $type
}, 'query-index', true())
};

And the last part you might need is something that is faster than a human when it comes to start requests like node with a bunch of superagent/supertest request promises:

Promise.all(requests)
.then(docs => {})

14:24:56.545    127.0.0.1:52592 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.546    127.0.0.1:52593 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.546    127.0.0.1:52595 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.546    127.0.0.1:52594 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.546    127.0.0.1:52596 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.547    127.0.0.1:52597 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.547    127.0.0.1:52598 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.548    127.0.0.1:52599 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.548    127.0.0.1:52600 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.549    127.0.0.1:52601 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.549    127.0.0.1:52602 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.550    127.0.0.1:52603 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.551    127.0.0.1:52604 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.551    127.0.0.1:52605 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.552    127.0.0.1:52606 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.552    127.0.0.1:52607 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.552    127.0.0.1:52608 admin   REQUEST [GET] http://localhost:8984/wde/...
14:24:56.554    127.0.0.1:52609 admin   REQUEST [GET] http://localhost:8984/wde/...

Best regards
Omar Siam

Am 29.11.2017 um 15:42 schrieb Christian Grün:
Hi Omar,

Thanks for reporting your observation.

What do you exactly mean by ”slave jobs”? Do you have some guidance
for us to make this reproducible?

Best,
Christian


On Wed, Nov 29, 2017 at 3:20 PM, Omar Siam <Omar.Siam@oeaw.ac.at> wrote:

Hi!

I just observed the following: If I start more RESTXQ requests than the
PARALLEL settings allows jobs, which start slave jobs and wait for them, the
RESTXQ jobs never finish, hang.

The RESTXQ jobs don't lock anything but start a slave job each which does
lock some DB for reading.

It seems to me that the RESTXQ requests are started regardless of the number
of parallel jobs already running but the slave jobs never start because they
are over the limit of parallel running jobs.

Is this a known situation? Is there some way to stop accepting RESTXQ
requests or not starting slave jobs until the parallel limit permits it?

Best regards

Omar Siam