add some doc to the thread-pool-executor props

Signed-off-by: Aleksandar Stanchev <[email protected]>

Author: alstanchev

connectivity/service/src/main/resources/connectivity.conf

@@ -1331,15 +1331,28 @@ http-push-connection-dispatcher {
   # The core-pool-size-min remains unchanged so its quite small (8). Unused threads will expire after 60s.
 
   thread-pool-executor {
+    # The core-pool-size-factor is used to determine corePoolSize of the
+    # ThreadPoolExecutor using the following formula:
+    # ceil(available processors * factor).
+    # Resulting size is then bounded by the core-pool-size-min and
+    # core-pool-size-max values.
+    # Increasing can help aleviate errors of type "Dropped message as result of backpressure strategy!" during high load.
     core-pool-size-factor = 4
     core-pool-size-factor = ${?HTTP_PUSH_CORE_POOL_SIZE_FACTOR}
-    core-pool-size-max = 64,
+    # Max number of threads to cap factor-based corePoolSize number to
+    core-pool-size-max = 64
     core-pool-size-max = ${?HTTP_PUSH_CORE_POOL_SIZE_MAX}
-    max-pool-size-min= 64,
-    max-pool-size-min= ${?HTTP_PUSH_CORE_POOL_SIZE_MAX}    # Overriding with the value of HTTP_PUSH_CORE_POOL_SIZE_MAX as if threads are a reason for http problems the pool normaly doesn't grow on its own so
-    # it is better to set the core upper limit manualy and this config will forse the core pool size to this value.
-    max-pool-size-max = 2147483647,
-    allow-core-timeout = on  # Enables timeout of core threads
+    # Minimum number of threads to cap factor-based maximumPoolSize number to
+    max-pool-size-min= 64
+    max-pool-size-min= ${?HTTP_PUSH_POOL_SIZE_MAX}
+    # Max number of threads to cap factor-based maximumPoolSize number to
+    max-pool-size-max = 512
+    max-pool-size-max= ${?HTTP_PUSH_POOL_SIZE_MAX}
+
+    # Allow core threads to time out
+    allow-core-timeout = on
+    # Keep alive time for threads
+    keep-alive-time = 60s
   }
 }
 
@@ -1368,5 +1381,6 @@ blocked-namespaces-dispatcher {
   throughput = 5
 }
 
+include "kamon.conf"
 include "connectivity-extension.conf"
 include file("/opt/ditto/connectivity-extension.conf")