Trying Caddy to see if it fixes connection issues on Jenkins

Author: rjrudin

caddy/config/Caddyfile

@@ -0,0 +1,21 @@
+# See https://caddyserver.com/docs/caddyfile-tutorial for more information.
+
+:8115 {
+  reverse_proxy marklogic:8015 {
+    transport http {
+      dial_timeout 31s
+    }
+    # Required for MLCP to work; "ip_hash" also works.
+    # See https://caddyserver.com/docs/caddyfile/directives/reverse_proxy#load-balancing for more information.
+    lb_policy cookie
+  }
+}
+
+:8116 {
+  reverse_proxy marklogic:8016 {
+    transport http {
+      dial_timeout 31s
+    }
+    lb_policy cookie
+  }
+}

docker-compose.yaml

@@ -2,6 +2,18 @@ name: marklogic_spark
 
 services:
 
+  # See https://caddyserver.com/docs/quick-starts/reverse-proxy for more information on using Caddy as a reverse proxy
+  # and load balancer.
+  caddy-load-balancer:
+    image: caddy:2-alpine
+    volumes:
+      - ./caddy/data:/data
+      - ./caddy/config/Caddyfile:/etc/caddy/Caddyfile
+    ports:
+      # Expand this range as needed. See Caddyfile for which ports are used for reverse proxies.
+      - "8115:8115"
+      - "8116:8116"
+
   marklogic:
     image: "${MARKLOGIC_TAG}"
     platform: linux/amd64

src/test/java/com/marklogic/spark/AbstractIntegrationTest.java

@@ -7,14 +7,15 @@
 import com.marklogic.client.io.DocumentMetadataHandle;
 import com.marklogic.junit5.XmlNode;
 import com.marklogic.junit5.spring.AbstractSpringMarkLogicTest;
-import com.marklogic.junit5.spring.SimpleTestConfig;
 import org.apache.spark.SparkException;
 import org.apache.spark.sql.*;
 import org.apache.spark.util.VersionUtils;
 import org.jdom2.Namespace;
 import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.core.io.ClassPathResource;
+import org.springframework.test.context.ContextConfiguration;
 import org.springframework.util.FileCopyUtils;
 
 import java.io.IOException;
@@ -31,6 +32,7 @@
  * <p>
  * Use this as the base class for all tests that need to connect to MarkLogic.
  */
+@ContextConfiguration(classes = {TestConfig.class})
 public abstract class AbstractIntegrationTest extends AbstractSpringMarkLogicTest {
 
     // User credentials for all calls to MarkLogic by the Spark connector
@@ -49,28 +51,20 @@ public abstract class AbstractIntegrationTest extends AbstractSpringMarkLogicTes
      * operations requiring an admin-like user.
      */
     @Autowired
-    protected SimpleTestConfig testConfig;
+    protected TestConfig testConfig;
 
     protected SparkSession sparkSession;
 
+    @BeforeEach
+    void logConnectionString() {
+        logger.info("Default connection string: {}", makeClientUri());
+    }
+
     @AfterEach
     public void closeSparkSession() {
         if (sparkSession != null) {
             sparkSession.close();
         }
-        smallDelayUntilNextTest();
-    }
-
-    // Tell Sonar not to worry about this for now.
-    @SuppressWarnings({"java:S2925"})
-    private void smallDelayUntilNextTest() {
-        // Hopefully a temporary hack to see if we get fewer random failures on Jenkins due to connectivity issues that
-        // are likely due to Docker restarting MarkLogic due to insufficient memory.
-        try {
-            Thread.sleep(100);
-        } catch (InterruptedException e) {
-            // No need to handle.
-        }
     }
 
     @Override

src/test/java/com/marklogic/spark/TestConfig.java

@@ -0,0 +1,15 @@
+/*
+ * Copyright © 2024 MarkLogic Corporation. All Rights Reserved.
+ */
+package com.marklogic.spark;
+
+import com.marklogic.junit5.spring.SimpleTestConfig;
+
+public class TestConfig extends SimpleTestConfig {
+
+    @Override
+    public Integer getRestPort() {
+        // Use the Caddy port to avoid connection failures on Jenkins.
+        return 8116;
+    }
+}

src/test/java/com/marklogic/spark/reader/triples/ReadTriplesTest.java

@@ -8,15 +8,13 @@
 import org.apache.spark.sql.DataFrameReader;
 import org.apache.spark.sql.Row;
 import org.apache.spark.sql.SaveMode;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
 import java.util.List;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-@Disabled("Annoying")
 class ReadTriplesTest extends AbstractIntegrationTest {
 
     @Test

src/test/java/com/marklogic/spark/writer/WriteRowsTest.java

@@ -77,7 +77,8 @@ void insufficientPrivilegeForOtherDatabase() {
         DataFrameWriter writer = newWriter(2)
             .option(Options.WRITE_THREAD_COUNT_PER_PARTITION, 8)
             .option(Options.WRITE_BATCH_SIZE, 10)
-            .option(Options.CLIENT_URI, "spark-test-user:spark@localhost:8016/Documents");
+            .option(Options.CLIENT_URI, String.format("spark-test-user:spark@%s:%d/Documents",
+                testConfig.getHost(), testConfig.getRestPort()));
 
         SparkException ex = assertThrows(SparkException.class, () -> writer.save());
         assertNull(ex.getCause(), "Surprisingly, in this scenario where the exception is thrown during the " +