with thanks to Jack Lloyd, this works around the default Botan allocator slowing down for us during production use.

ahupowerdns · mind04 · commit d71a712b3c7d · 2014-12-22T20:36:18.000+01:00
diff --git a/pdns/botansigners.cc b/pdns/botansigners.cc
@@ -255,6 +255,8 @@ struct LoaderBotanStruct
   {
     new Botan::LibraryInitializer("thread_safe=true");
     // this leaks, but is fine
+    Botan::global_state().set_default_allocator("malloc"); // the other Botan allocator slows down for us
+  
     DNSCryptoKeyEngine::report(5, &BotanRSADNSCryptoKeyEngine::maker);
     DNSCryptoKeyEngine::report(7, &BotanRSADNSCryptoKeyEngine::maker);
     DNSCryptoKeyEngine::report(8, &BotanRSADNSCryptoKeyEngine::maker);

Original file line number	Diff line number	Diff line change
`@@ -255,6 +255,8 @@ struct LoaderBotanStruct`
`255`	`255`	`{`
`256`	`256`	`new Botan::LibraryInitializer("thread_safe=true");`
`257`	`257`	`// this leaks, but is fine`
	`258`	`+ Botan::global_state().set_default_allocator("malloc"); // the other Botan allocator slows down for us`
	`259`	`+`
`258`	`260`	`DNSCryptoKeyEngine::report(5, &BotanRSADNSCryptoKeyEngine::maker);`
`259`	`261`	`DNSCryptoKeyEngine::report(7, &BotanRSADNSCryptoKeyEngine::maker);`
`260`	`262`	`DNSCryptoKeyEngine::report(8, &BotanRSADNSCryptoKeyEngine::maker);`