Fix dark cluster URI rewrite deopt storm consuming 80% CPU

CHANGELOG.md

@@ -14,6 +14,10 @@ and what APIs have changed, if applicable.
 
 ## [Unreleased]
 
+## [29.85.7-rc.5] - 2026-04-08
+
+Testing darkcluster deop storm fix.
+
 ## [29.85.6] - 2026-03-06
 - Add cluster subsetting configuration (enableClusterSubsetting, minClusterSubsetSize) to D2Cluster and ClusterProperties.
 
@@ -5973,7 +5977,8 @@ patch operations can re-use these classes for generating patch messages.
 
 ## [0.14.1]
 
-[Unreleased]: https://github.com/linkedin/rest.li/compare/v29.85.6...master
+[Unreleased]: https://github.com/linkedin/rest.li/compare/v29.85.7-rc.5...master
+[29.85.7-rc.5]: https://github.com/linkedin/rest.li/compare/v29.85.6...v29.85.7-rc.5
 [29.85.6]: https://github.com/linkedin/rest.li/compare/v29.85.5...v29.85.6
 [29.85.5]: https://github.com/linkedin/rest.li/compare/v29.85.4...v29.85.5
 [29.85.4]: https://github.com/linkedin/rest.li/compare/v29.85.3...v29.85.4

d2/src/main/java/com/linkedin/d2/balancer/util/D2URIRewriter.java

@@ -19,8 +19,6 @@
 import com.linkedin.jersey.api.uri.UriBuilder;
 import com.linkedin.util.ArgumentUtil;
 import java.net.URI;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
 
 /**
@@ -29,7 +27,6 @@
 
 public class D2URIRewriter implements URIRewriter
 {
-  final private static Logger LOGGER = LoggerFactory.getLogger(D2URIRewriter.class);
   final private URI _httpURI;
 
   public D2URIRewriter(URI httpURI)
@@ -47,12 +44,8 @@ public URI rewriteURI(URI d2Uri)
     {
       builder.path(path);
     }
-    builder.replaceQuery(d2Uri.getRawQuery());
+    builder.replaceQueryFrom(d2Uri);
     builder.fragment(d2Uri.getRawFragment());
-    URI rewrittenUri = builder.build();
-
-    LOGGER.debug("rewrite uri {} -> {}", d2Uri, rewrittenUri);
-
-    return rewrittenUri;
+    return builder.build();
   }
 }

d2/src/test/java/com/linkedin/d2/balancer/util/TestD2URIRewriter.java

@@ -18,8 +18,11 @@
 
 import java.net.URI;
 import java.net.URISyntaxException;
+import java.util.ArrayList;
+import java.util.List;
 import org.apache.http.client.utils.URIBuilder;
 import org.testng.Assert;
+import org.testng.annotations.DataProvider;
 import org.testng.annotations.Test;
 
 
@@ -40,4 +43,128 @@ public void testSimpleD2Rewrite() throws URISyntaxException
     URI finalURI = URIRewriter.rewriteURI(d2URI);
     Assert.assertEquals(finalURI.toString(), expectURL);
   }
+
+  @Test
+  public void testRewriteWithEncodedQuery() throws URISyntaxException
+  {
+    final URI httpURI = new URIBuilder("http://www.linkedin.com:1234/test").build();
+    final URI d2URI = URI.create("d2://serviceName/request/query?q=hello%20world&name=foo%26bar");
+    final String expectURL = "http://www.linkedin.com:1234/test/request/query?q=hello%20world&name=foo%26bar";
+
+    URI result = new D2URIRewriter(httpURI).rewriteURI(d2URI);
+    Assert.assertEquals(result.toString(), expectURL);
+  }
+
+  @Test
+  public void testRewriteNoQuery() throws URISyntaxException
+  {
+    final URI httpURI = new URIBuilder("http://www.linkedin.com:1234/test").build();
+    final URI d2URI = URI.create("d2://serviceName/request/path");
+    final String expectURL = "http://www.linkedin.com:1234/test/request/path";
+
+    URI result = new D2URIRewriter(httpURI).rewriteURI(d2URI);
+    Assert.assertEquals(result.toString(), expectURL);
+  }
+
+  @Test
+  public void testRewriteWithFragment() throws URISyntaxException
+  {
+    final URI httpURI = new URIBuilder("http://www.linkedin.com:1234").build();
+    final URI d2URI = URI.create("d2://serviceName/path?q=1#section");
+    final String expectURL = "http://www.linkedin.com:1234/path?q=1#section";
+
+    URI result = new D2URIRewriter(httpURI).rewriteURI(d2URI);
+    Assert.assertEquals(result.toString(), expectURL);
+  }
+
+  /**
+   * Verify that rewriting preserves percent-encoded characters in query strings.
+   * Uses {@link com.linkedin.jersey.api.uri.UriBuilder#replaceQueryFrom(URI)} which copies
+   * the raw query directly, avoiding character-by-character re-encoding.
+   */
+  @DataProvider(name = "asciiQueryCharsEncoded")
+  public Object[][] asciiQueryCharsEncoded()
+  {
+    List<Object[]> cases = new ArrayList<>();
+    for (int c = 0x20; c <= 0x7E; c++)
+    {
+      // Every character in its percent-encoded form — this is how characters arrive
+      // in real RestRequest URIs from the HTTP layer.
+      String percentEncoded = String.format("%%%02X", c);
+      cases.add(new Object[]{
+          "percent-encoded 0x" + String.format("%02X", c) + " '" + (char) c + "'",
+          "/path?q=" + percentEncoded
+      });
+    }
+
+    // Realistic rest.li query strings
+    cases.add(new Object[]{"restli query", "/myResource/1?q=findByName&name=hello%20world"});
+    cases.add(new Object[]{"restli complex query",
+        "/myResource?q=search&keywords=java%20engineer&start=0&count=10&fields=id,firstName,lastName"});
+    cases.add(new Object[]{"restli batch get",
+        "/myResource?ids=List(1,2,3)&fields=id,name"});
+    cases.add(new Object[]{"query with encoded special chars",
+        "/myResource?filter=(key%3Avalue)&sort=name%26date"});
+    cases.add(new Object[]{"restli encoded brackets",
+        "/myResource?criteria%5B0%5D=valueA&criteria%5B1%5D=valueB"});
+
+    return cases.toArray(new Object[0][]);
+  }
+
+  @Test(dataProvider = "asciiQueryCharsEncoded")
+  public void testRewritePreservesEncodedQuery(String description, String uriString)
+  {
+    URI configuredURI = URI.create("d2://testService");
+    D2URIRewriter rewriter = new D2URIRewriter(configuredURI);
+
+    URI input = URI.create(uriString);
+    URI result = rewriter.rewriteURI(input);
+
+    // The raw query should be preserved exactly as-is
+    Assert.assertEquals(result.getRawQuery(), input.getRawQuery(),
+        "Query not preserved for [" + description + "] input=" + uriString);
+  }
+
+  @DataProvider(name = "asciiQueryCharsLiteral")
+  public Object[][] asciiQueryCharsLiteral()
+  {
+    List<Object[]> cases = new ArrayList<>();
+    for (int c = 0x20; c <= 0x7E; c++)
+    {
+      // # terminates query, % needs hex pair
+      if (c == '#' || c == '%')
+      {
+        continue;
+      }
+
+      String literal = "/path?q=" + (char) c;
+      try
+      {
+        URI.create(literal);
+        cases.add(new Object[]{
+            "literal 0x" + String.format("%02X", c) + " '" + (char) c + "'",
+            literal
+        });
+      }
+      catch (IllegalArgumentException e)
+      {
+        // Character not valid in URI.create — skip
+      }
+    }
+    return cases.toArray(new Object[0][]);
+  }
+
+  @Test(dataProvider = "asciiQueryCharsLiteral")
+  public void testRewritePreservesLiteralQuery(String description, String uriString)
+  {
+    URI configuredURI = URI.create("d2://testService");
+    D2URIRewriter rewriter = new D2URIRewriter(configuredURI);
+
+    URI input = URI.create(uriString);
+    URI result = rewriter.rewriteURI(input);
+
+    // The raw query should be preserved exactly as-is
+    Assert.assertEquals(result.getRawQuery(), input.getRawQuery(),
+        "Query not preserved for [" + description + "] input=" + uriString);
+  }
 }

darkcluster/src/test/java/com/linkedin/darkcluster/TestDarkClusterUrlRewrite.java

@@ -51,4 +51,17 @@ public void testRewriteWithQueryParams()
     URI outputURI = rewriter.rewriteURI(inputUri);
     Assert.assertEquals(outputURI, expectedURI, "URI's don't match");
   }
+
+  @Test
+  public void testRewriteWithEncodedQueryParams()
+  {
+    String darkServiceName = "FooCluster-dark";
+    URI configuredURI = URI.create("d2://" + darkServiceName);
+    D2URIRewriter rewriter = new D2URIRewriter(configuredURI);
+
+    URI inputUri = URI.create("/MyRestliResource/foo/1?param1=hello%20world&param2=a%26b%3Dc");
+    URI expectedURI = URI.create("d2://"+ darkServiceName + "/MyRestliResource/foo/1?param1=hello%20world&param2=a%26b%3Dc");
+    URI outputURI = rewriter.rewriteURI(inputUri);
+    Assert.assertEquals(outputURI, expectedURI, "URI's don't match");
+  }
 }

gradle.properties

@@ -1,4 +1,4 @@
-version=29.85.6
+version=29.85.7-rc.7
 group=com.linkedin.pegasus
 org.gradle.configureondemand=true
 org.gradle.parallel=true

li-jersey-uri/src/main/java/com/linkedin/jersey/api/uri/UriBuilder.java

@@ -453,6 +453,22 @@ public UriBuilder replaceQuery(String query) {
         return this;
     }
 
+    /**
+     * Replace the query string with the raw (already percent-encoded) query from the given URI.
+     * This avoids the expensive character-by-character re-encoding in {@link #replaceQuery(String)}
+     * when the source is a {@link URI} whose query is already properly encoded.
+     * @param uri the URI whose raw query string to copy
+     * @return this
+     */
+    public UriBuilder replaceQueryFrom(URI uri) {
+        checkSsp();
+        this.query.setLength(0);
+        String rawQuery = uri.getRawQuery();
+        if (rawQuery != null)
+            this.query.append(rawQuery);
+        return this;
+    }
+
     /**
      * add the given queryParam and its value(s) to the UriBuilder
      * @param name name of the queryParam