Failed to create thread: Resource temporarily unavailable (11) in RdKafkaContext.php line 96 #1298

Hi all, I am a little stuck with this so I would some guidance as to where to look. I recently updated from 0.10.1 to 0.10.8 of the rdkafka library which is the maximum I can bump to currently due to php version.

librdkafka: 1.9.1
pecl rdkafka: 3.0.3

I do understand that these are more than 'outdated' but we are stuck for the moment whilst we do a sizeable update.

Since updating and deploying I am now seeing the consistent exception:

Failed to create thread: Resource temporarily unavailable (11) in file [remove]/vendor/enqueue/rdkafka/RdKafkaContext.php line 96

I can see substantial changes to RdKafaContext::createProducer() between 0.10.1 and 0.10.8(for example this introduced in 0.10.4) however I do not know if they bear any responsibility for the reported exceptions or if its something further down in the request chain.

Any help on this is massively appreciated.