Added custom executor for grpc server with fixed 20 threads. Default thread pool is unbounded :(

src/main/kotlin/io/emeraldpay/dshackle/GrpcServer.kt

@@ -16,6 +16,7 @@
  */
 package io.emeraldpay.dshackle
 
+import com.google.common.util.concurrent.ThreadFactoryBuilder
 import io.emeraldpay.dshackle.config.MainConfig
 import io.emeraldpay.dshackle.monitoring.accesslog.AccessHandlerGrpc
 import io.grpc.Server
@@ -24,6 +25,7 @@ import org.slf4j.LoggerFactory
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.stereotype.Service
 import java.net.InetSocketAddress
+import java.util.concurrent.Executors
 import javax.annotation.PostConstruct
 import javax.annotation.PreDestroy
 
@@ -63,6 +65,13 @@ open class GrpcServer(
             serverBuilder.addService(it)
         }
 
+        serverBuilder.executor(
+            Executors.newFixedThreadPool(
+                20,
+                ThreadFactoryBuilder().setNameFormat("custom-grpc-%d").build()
+            )
+        )
+
         val server = serverBuilder.build()
         this.server = server