chore(bqjdbc): switch connection identifier to UUID

java-bigquery/google-cloud-bigquery-jdbc/src/main/java/com/google/cloud/bigquery/jdbc/BigQueryConnection.java

@@ -61,7 +61,6 @@
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicLong;
 
 /**
  * An implementation of {@link java.sql.Connection} for establishing a connection with BigQuery and
@@ -74,7 +73,6 @@ public class BigQueryConnection extends BigQueryNoOpsConnection {
   private final BigQueryJdbcCustomLogger LOG = new BigQueryJdbcCustomLogger(this.toString());
   String connectionClassName = this.toString();
   private final String connectionId;
-  private static final AtomicLong connectionIdCounter = new AtomicLong(1);
   private static final String DEFAULT_JDBC_TOKEN_VALUE = "Google-BigQuery-JDBC-Driver";
   private static final String DEFAULT_VERSION = "0.0.0";
   private HeaderProvider headerProvider;
@@ -149,7 +147,7 @@ public class BigQueryConnection extends BigQueryNoOpsConnection {
   }
 
   BigQueryConnection(String url, DataSource ds) throws IOException {
-    this.connectionId = String.valueOf(connectionIdCounter.getAndIncrement());
+    this.connectionId = BigQueryJdbcMdc.generateConnectionId();
     try (BigQueryJdbcMdc.MdcCloseable mdc =
         BigQueryJdbcMdc.registerInstance(this, this.connectionId)) {
       LOG.finest("++enter++");

java-bigquery/google-cloud-bigquery-jdbc/src/main/java/com/google/cloud/bigquery/jdbc/BigQueryJdbcMdc.java

@@ -16,16 +16,17 @@
 
 package com.google.cloud.bigquery.jdbc;
 
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.atomic.AtomicLong;
 
 /**
  * Lightweight MDC implementation for the BigQuery JDBC driver using InheritableThreadLocal.
  * Allocates a dedicated, independent InheritableThreadLocal object per concrete BigQueryConnection
  * instance.
  */
 class BigQueryJdbcMdc {
-  private static final AtomicLong nextId = new AtomicLong(1);
   private static final ConcurrentHashMap<BigQueryConnection, InheritableThreadLocal<String>>
       instanceLocals = new ConcurrentHashMap<>();
   private static final ConcurrentHashMap<BigQueryConnection, String> instanceIds =
@@ -35,15 +36,20 @@ class BigQueryJdbcMdc {
   private static final InheritableThreadLocal<String> currentConnectionId =
       new InheritableThreadLocal<>();
 
+  static String generateConnectionId() {
+    String timestamp = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyyMMdd-HHmmss"));
+    String shortUuid = UUID.randomUUID().toString().substring(0, 8);
+    return timestamp + "-" + shortUuid;
+  }
+
   static MdcCloseable registerInstance(BigQueryConnection connection, String id) {
     if (connection != null) {
       String cleanId =
           instanceIds.computeIfAbsent(
               connection,
               k -> {
-                String suffix =
-                    (id != null && !id.isEmpty()) ? id : String.valueOf(nextId.getAndIncrement());
-                return "JdbcConnection-" + suffix;
+                String baseId = (id != null && !id.isEmpty()) ? id : generateConnectionId();
+                return "JdbcConnection-" + baseId;
               });
 
       currentConnectionId.set(cleanId);