Re: JMeter timer scoping issue

Jun Zhuang wrote:
> Hi,
>
> I am seeing unexpected behavior with the timer scoping. I am not using 
> any timer for requests in the 1st half of my test plan (DB operations 
> only) and only using the Gaussian timer (2 - 4 secs) in the 2nd half 
> of the test, i.e., in the === Create Sample Batching Job === simple 
> controller, but it seems to be applied universally anyway. The reason 
> I am saying "applied universally" is because the test runs very fast 
> in GUI mode (~ 1 min) when I use the run without pause option or in 
> non-GUI mode by setting the timer to 0.
>
> When I use the 2-4 seconds setting in non-GUI mode, the test ran for 
> more than 5 MINUTES and mostly in the 1st half the DB query part.
>
> The timer is placed within the last request in each of the 
> transactions, so my understanding is it will only happen after the 
> last request in each transaction.
>
> Inline image
>
> Thanks.
> Jun
> On Saturday, December 2, 2023 at 01:06:06 PM EST, Jun Zhuang 
> <[email protected]> wrote:
>
>
> Got it working. Thanks again for your help Felix!
>
> 3 things I had to do:
>
>  1. Use TWO double quotes for every double quote, so {"name":
>     "whatever"} becomes {""name"": ""whatever""}
>  2. Put the final JSON string in double quotes when making the
>     insertion request. Single quotes don't work!
>  3. In the JDBC request for insert, specify the data type as varchar
>     instead of text even though text is the data type for the column I
>     am inserting to. Otherwise, the inert will throw "invalid data
>     type: text" error.
>
>
> So as in your example, the following should be supplied for the 
> insert: "{""name"": ""whatever""}"
>
> Jun
> On Saturday, December 2, 2023 at 08:49:39 AM EST, Felix Schumacher 
> <[email protected]> wrote:
>
>
> Hi Jun,
>
> I have attached a working minimal example, that uses a JSON string and 
> inserts that with a prepared statement.
>
> It assumes a locally running postgres which can be changed of course.
>
> The interesting part is:
>
> * You have to escape comma and quotes in the JSON string.
>   Given a JSON object like {"name": "whatever"} you will have to add 
> quotes to mask the comma and quotes to mask the quotes.
>   Your string will have to look like "{""name"": ""whatever""}"
>
> * You have to cast the parameter to json in your insert statement.
>   Add a ::json to the placeholder, as in "insert into something values 
> (?::json)"
>
> Regards
>
>  Felix
>
> Am 02.12.23 um 14:19 schrieb Jun Zhuang:
> Hi Filex,
>
> Thanks for the response. I tried with the single quotes and singles 
> quotes + ::json, still got the same error.
>
> Just to be sure, are you using a Postgres DB? Also one thing I forgot 
> to mentioned in my original email was the field I am trying to insert 
> into is of data type *text* instead of varchar, I wonder if that makes 
> any difference?
>
> Following are some screenshots of what I am trying to do:
>
> Inline image
>
>
> Inline image
>
>
> Inline image
>
>
>
> On Saturday, December 2, 2023 at 05:58:52 AM EST, Felix Schumacher 
> <[email protected] 
> <mailto:[email protected]>> wrote:
>
>
>
>
>
>
> Hi Jun,
>
> I am not sure, what you tried already. When I place the following text 
> into a JDBC Sampler's query field, I get no errors:
>
> create table something (id int, data json);
> insert into something values (1, '{"name": "whatever"}'::json);
>
> Same result, when I remove the casting and use
>
> create table something (id int, data json);
> insert into something values (1, '{"name": "whatever"}');
>
> Can you show us a minimal example that fails for you?
>
>
>
>
>
> Regards
>
>  Felix
>
>
>
>
> Am 01.12.23 um 23:24 schrieb Jun Zhuang:
>
>
> >  Hi,
> > I am getting Cannot have quote-char in plain field:['{"] error when 
> trying to insert a JSON string into a Postgres DB table using JDBC 
> request.
> > I tried the following but nothing worked:
> >    - place the JSON string in single quotes,
> >    - escaping the double quotes with \",
> >    - placing the string in $$<JSON string here>$$ but nothing worked.
> > There is no issue with the connection and other select/insert 
> queries and I was able to insert from pgAdmin with the same string in 
> single quotes though.
> > The JSON string looks like this: {"A":"A", "B":[{"C":"C"}]}
> > I am really out of ideas at this time. Can someone help?
> > Thanks,Jun
> >
> >
>
>
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Timers are executed *before* each Sampler it their scope. If you want it 
to be executed after all Samplers you need to add a Flow Control Action 
<https://jmeter.apache.org/usermanual/component_reference.html#Flow_Control_Action> 
sampler and make the timer a child of this sampler. Or Flow Control 
Action sampler can create delay on its own exactly where it's placed.

More information:

  * Scoping Rules
    <https://jmeter.apache.org/usermanual/test_plan.html#scoping_rules>
  * A Comprehensive Guide to Using JMeter Timers
    <https://www.blazemeter.com/blog/jmeter-timer>