Currently the Webdesigner makes up to 6(?) and the Standalone Designer as much as it needs without(?) limit.

Especially the latter case can quickly lead to a lot of connections, saturating the max allowed connections of a sql server, which also leads to other services depending on a sql server connection to fail.

As far as I've seen, this only happens with Charts in Design mode.

So there are multiple ways to handle this:

• Being able to specify the max concurrent connections in the designer
• Make the usage of the DataSource more efficient by only loading the data once (like in the report viewer)
• Being able to turn off the chart preview in the Designer (By configuration, not with a user settable option)

See the attached report for a simple example:

It contains a single Datasource, which is a postgres query which simply waits 10s before returning the result.
After updating the DataSource to something which works for you and saving, simply reopen the report and see how many connections are opened in parallel.

With kind regards
Dominik Rothert