Merge pull request #34 from alex268/release_v2.0.4

Force using of single thread scheduler

jdbc/src/main/java/tech/ydb/jdbc/context/YdbContext.java

@@ -3,6 +3,7 @@
 import java.sql.SQLException;
 import java.util.Map;
 import java.util.Objects;
+import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.logging.Level;
 import java.util.logging.Logger;
@@ -148,6 +149,17 @@ public static GrpcTransport buildGrpcTransport(YdbConnectionProperties props) {
             builder = builder.withAuthProvider(props.getStaticCredentials());
         }
 
+        // Use custom single thread scheduler because JDBC driver doesn't need to execute retries except for DISCOERY
+        builder.withSchedulerFactory(() -> {
+            final String namePrefix = "ydb-jdbc-scheduler[" + props.hashCode() +"]-thread-";
+            final AtomicInteger threadNumber = new AtomicInteger(1);
+            return Executors.newScheduledThreadPool(1, (Runnable r) -> {
+                Thread t = new Thread(r, namePrefix + threadNumber.getAndIncrement());
+                t.setDaemon(true);
+                return t;
+            });
+        });
+
         return builder.build();
     }