I searched all the settings, looking for the option for configuring the maximum number of concurrent DNS queries.
It was only after web search, that I learned that this configuration option is not in the settings, currently.
Please add an option for configuring the maximum number of concurrent DNS queries, or make it clear that it is not possible to configure the maximum number of concurrent DNS queries in the Pi-hole settings.
Set the maximum number of concurrent DNS queries.
The default value is 150, which should be fine for most setups.
The only known situation where this needs to be increased is when using web-server log file resolvers, which can generate large numbers of concurrent queries.
Important note:
The default value is fine for 99% of the use cases. When this message appears, it usually means there is something wrong with your upstream server (or there is a DNS loop). In this case, you should try to find out why you have more than 150 concurrent DNS requests.
Are you positive that it's actually necessary to adjust your dnsmasq's dns-forward-max?
The warning's description currently tries to nudge users to identify the root cause.
When dealing with dozens of Maximum number of concurrent DNS queries reached reports, adjusting the default value never actually solved an issue - they were solved by addressing the root cause.
In the majority of such reports, a DNS loop of sorts was triggering the warning, less often a (temporarily) inaccessible upstream, or clients excessively requesting resolution (e.g. some monitoring tools hitting DNS with entire network range reverse lookups every two hundred milliseconds).
Consequently, the issue could be appropriately dealt with by avoiding the DNS loop, making the upstream accessible or switching to a reliably accessible one, or adjusting the client configuration.
ETA_2024, I think I understand your point, but I don't agree we should add this suggestion to the settings.
We really think the default value works for almost 100% of the cases.
We also think the usual fix for the message Maximum number of concurrent DNS queries reached (max: 150) is to find the cause of the high number of concurrent queries, not increase this value.
As explained by Bucking_Horn:
If we add this suggestion to the settings text, most users will think this is the correct way to deal with the issue and they will try to increase this value, but in cases of loops or inaccessible upstream, increasing this number won't help at all.
