In
server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java
around lines 1035-1042, the logger.warn call is using parameterized message and
passing the exception in the middle of the varargs which triggers "Bad usage of
logger"; ensure the Throwable is the final argument by calling
logger.warn("Exception while deleting segment files corresponding to metadata
file {}. Deletion will be re-tried", metadataFile, e) so the metadataFile fills
the placeholder and the exception is passed as the last parameter to be logged
with the stack trace.

In
server/src/test/java/org/opensearch/index/store/RemoteSegmentStoreDirectoryTests.java
around lines 1181-1188, the test incorrectly checks cache keys using remote
filenames (which include the "__uuid" suffix) while the cache stores local
filenames (without the suffix), so the assertion always passes; to fix, convert
each entry in expectedFilesToDelete to the local filename before asserting
(e.g., strip the "__" and trailing UUID part or parse until the first "__" and
use that substring), then assert that cacheAfter does not
containKey(localFilename) for each converted name, ensuring the cache
verification actually validates removal.

#!/bin/bash
# Check how segmentsUploadedToRemoteStore is populated and what keys it uses
echo "=== Searching for segmentsUploadedToRemoteStore usage ==="
rg -n -C5 'segmentsUploadedToRemoteStore\.put' --type=java

echo -e "\n=== Checking UploadedSegmentMetadata and cache key structure ==="
rg -n -C3 'class.*UploadedSegmentMetadata' --type=java

echo -e "\n=== Looking at how cache is accessed with containsKey ==="
rg -n -C3 'segmentsUploadedToRemoteStore.*containsKey' --type=java

#!/bin/bash
# Look at the actual deletion implementation to understand cache update
echo "=== Searching for deleteStaleCommits or deleteStale in RemoteSegmentStoreDirectory ==="
ast-grep --pattern 'deleteStale$$$($$$) {
  $$$
}'

echo -e "\n=== Check how cache entries are removed after deletion ==="
rg -n -C5 'segmentsUploadedToRemoteStore\.remove' --type=java

#!/bin/bash
# Look at the metadata format and how local vs remote filenames are used
echo "=== Check SEGMENT_NAME_UUID_SEPARATOR usage ==="
rg -n -C3 'SEGMENT_NAME_UUID_SEPARATOR' --type=java server/src/main/java/org/opensearch/index/store/

echo -e "\n=== Check how metadata maps local to remote names ==="
rg -n -C5 'getMetadata\(\)' --type=java server/src/main/java/org/opensearch/index/store/RemoteSegmentStoreDirectory.java

public static class MetadataFilenameUtils {
        public static final String SEPARATOR = "__";
        public static final String METADATA_PREFIX = "metadata";

        static String getMetadataFilePrefixForCommit(long primaryTerm, long generation) {
            return String.join(
                SEPARATOR,
                METADATA_PREFIX,
                RemoteStoreUtils.invertLong(primaryTerm),
                RemoteStoreUtils.invertLong(generation)
            );
        }

        // Visible for testing
        public static String getMetadataFilename(
            long primaryTerm,
            long generation,
            long translogGeneration,
            long uploadCounter,
            int metadataVersion,
            String nodeId,
            long creationTimestamp
        ) {
            return String.join(
                SEPARATOR,
                METADATA_PREFIX,
                RemoteStoreUtils.invertLong(primaryTerm),
                RemoteStoreUtils.invertLong(generation),
                RemoteStoreUtils.invertLong(translogGeneration),
                RemoteStoreUtils.invertLong(uploadCounter),
                String.valueOf(Objects.hash(nodeId)),
                RemoteStoreUtils.invertLong(creationTimestamp),
                String.valueOf(metadataVersion)
            );
        }

        public static String getMetadataFilename(
            long primaryTerm,
            long generation,
            long translogGeneration,
            long uploadCounter,
            int metadataVersion,
            String nodeId
        ) {
            return getMetadataFilename(
                primaryTerm,
                generation,
                translogGeneration,
                uploadCounter,
                metadataVersion,
                nodeId,
                System.currentTimeMillis()
            );
        }

        // Visible for testing
        static long getPrimaryTerm(String[] filenameTokens) {
            return RemoteStoreUtils.invertLong(filenameTokens[1]);
        }

        // Visible for testing
        static long getGeneration(String[] filenameTokens) {
            return RemoteStoreUtils.invertLong(filenameTokens[2]);
        }

        public static long getTimestamp(String filename) {
            String[] filenameTokens = filename.split(SEPARATOR);
            return RemoteStoreUtils.invertLong(filenameTokens[filenameTokens.length - 2]);
        }

        public static Tuple<String, String> getNodeIdByPrimaryTermAndGen(String filename) {
            String[] tokens = filename.split(SEPARATOR);
            if (tokens.length < 8) {
                // For versions < 2.11, we don't have node id.
                return null;
            }
            String primaryTermAndGen = String.join(SEPARATOR, tokens[1], tokens[2], tokens[3]);

            String nodeId = tokens[5];
            return new Tuple<>(primaryTermAndGen, nodeId);
        }

    }

        // Visible for testing
        static long getPrimaryTerm(String[] filenameTokens) {
            return RemoteStoreUtils.invertLong(filenameTokens[1]);
        }

        // Visible for testing
        static long getGeneration(String[] filenameTokens) {
            return RemoteStoreUtils.invertLong(filenameTokens[2]);
        }

        public static long getTimestamp(String filename) {
            String[] filenameTokens = filename.split(SEPARATOR);
            return RemoteStoreUtils.invertLong(filenameTokens[filenameTokens.length - 2]);
        }

        public static Tuple<String, String> getNodeIdByPrimaryTermAndGen(String filename) {
            String[] tokens = filename.split(SEPARATOR);
            if (tokens.length < 8) {
                // For versions < 2.11, we don't have node id.
                return null;
            }
            String primaryTermAndGen = String.join(SEPARATOR, tokens[1], tokens[2], tokens[3]);

            String nodeId = tokens[5];
            return new Tuple<>(primaryTermAndGen, nodeId);
        }