Add LogPatternTool

src/main/java/org/opensearch/agent/ToolPlugin.java

@@ -12,6 +12,7 @@
 
 import org.opensearch.agent.tools.CreateAlertTool;
 import org.opensearch.agent.tools.CreateAnomalyDetectorTool;
+import org.opensearch.agent.tools.LogPatternTool;
 import org.opensearch.agent.tools.NeuralSparseSearchTool;
 import org.opensearch.agent.tools.PPLTool;
 import org.opensearch.agent.tools.RAGTool;
@@ -71,6 +72,7 @@
         SearchMonitorsTool.Factory.getInstance().init(client);
         CreateAlertTool.Factory.getInstance().init(client);
         CreateAnomalyDetectorTool.Factory.getInstance().init(client);
+        LogPatternTool.Factory.getInstance().init(client, xContentRegistry);
         return Collections.emptyList();
     }
 
@@ -87,7 +89,8 @@
                 SearchAnomalyResultsTool.Factory.getInstance(),
                 SearchMonitorsTool.Factory.getInstance(),
                 CreateAlertTool.Factory.getInstance(),
-                CreateAnomalyDetectorTool.Factory.getInstance()
+                CreateAnomalyDetectorTool.Factory.getInstance(),
+                LogPatternTool.Factory.getInstance()
             );
     }
 

src/main/java/org/opensearch/agent/tools/AbstractRetrieverTool.java

@@ -77,7 +77,7 @@ private static Map<String, Object> processResponse(SearchHit hit) {
         return docContent;
     }
 
-    private <T> SearchRequest buildSearchRequest(Map<String, String> parameters) throws IOException {
+    protected <T> SearchRequest buildSearchRequest(Map<String, String> parameters) throws IOException {
         String question = parameters.get(INPUT_FIELD);
         if (StringUtils.isBlank(question)) {
             throw new IllegalArgumentException("[" + INPUT_FIELD + "] is null or empty, can not process it.");
@@ -89,8 +89,7 @@ private <T> SearchRequest buildSearchRequest(Map<String, String> parameters) thr
         searchSourceBuilder.parseXContent(queryParser);
         searchSourceBuilder.fetchSource(sourceFields, null);
         searchSourceBuilder.size(docSize);
-        SearchRequest searchRequest = new SearchRequest().source(searchSourceBuilder).indices(index);
-        return searchRequest;
+        return new SearchRequest().source(searchSourceBuilder).indices(parameters.getOrDefault(INDEX_FIELD, index));
     }
 
     @Override

src/main/java/org/opensearch/agent/tools/LogPatternTool.java

@@ -0,0 +1,294 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.agent.tools;
+
+import static org.opensearch.ml.common.utils.StringUtils.gson;
+
+import java.security.AccessController;
+import java.security.PrivilegedExceptionAction;
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang3.StringUtils;
+import org.opensearch.action.search.SearchRequest;
+import org.opensearch.action.search.SearchResponse;
+import org.opensearch.client.Client;
+import org.opensearch.core.action.ActionListener;
+import org.opensearch.core.common.logging.LoggerMessageFormat;
+import org.opensearch.core.xcontent.NamedXContentRegistry;
+import org.opensearch.ml.common.spi.tools.ToolAnnotation;
+import org.opensearch.search.SearchHit;
+
+import com.google.common.annotations.VisibleForTesting;
+import com.google.common.collect.ImmutableSet;
+
+import lombok.Builder;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+import lombok.extern.log4j.Log4j2;
+
+/**
+ * This tool supports generating log patterns on the input dsl and index. It's implemented by
+ * several steps:
+ * 1. Retrival [[${DOC_SIZE_FIELD}]] logs from index
+ * 2. Extract patterns for each retrieved log
+ *  2.1 Find Pattern Field: If users provide parameter [[${PATTERN_FIELD}]], use it as the pattern
+ *      field; Otherwise, find the string field with the longest length on the first log.
+ *  2.2 Extract Pattern: If users provide parameter [[${PATTERN}]], compile it as a pattern;
+ *      Otherwise, use [[${DEFAULT_IGNORED_CHARS}]]. It will remove all chars matching the pattern.
+ * 3. Group logs by their extracted patterns.
+ * 4. Find top N patterns with the largest sample log size.
+ * 5. For each found top N patterns, return [[${SAMPLE_LOG_SIZE}]] sample logs.
+ */
+@Log4j2
+@Getter
+@Setter
+@ToolAnnotation(LogPatternTool.TYPE)
+public class LogPatternTool extends AbstractRetrieverTool {
+    public static final String TYPE = "LogPatternTool";
+
+    public static final String DEFAULT_DESCRIPTION = "Log Pattern Tool";
+    public static final String TOP_N_PATTERN = "top_n_pattern";
+    public static final String SAMPLE_LOG_SIZE = "sample_log_size";
+    public static final String PATTERN_FIELD = "pattern_field";
+    public static final String PATTERN = "pattern";
+    public static final int LOG_PATTERN_DEFAULT_DOC_SIZE = 1000;
+    public static final int DEFAULT_TOP_N_PATTERN = 3;
+    public static final int DEFAULT_SAMPLE_LOG_SIZE = 20;
+    private static final ImmutableSet<Character> DEFAULT_IGNORED_CHARS = ImmutableSet
+        .copyOf("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".chars().mapToObj(c -> (char) c).toArray(Character[]::new));
+
+    private String name = TYPE;
+    private int topNPattern;
+    private int sampleLogSize;
+    @EqualsAndHashCode.Exclude
+    private Pattern pattern;
+
+    @Builder
+    public LogPatternTool(
+        Client client,
+        NamedXContentRegistry xContentRegistry,
+        int docSize,
+        int topNPattern,
+        int sampleLogSize,
+        String patternStr
+    ) {
+        super(client, xContentRegistry, null, null, docSize);
+        checkPositive(topNPattern, TOP_N_PATTERN);
+        checkPositive(sampleLogSize, SAMPLE_LOG_SIZE);
+        this.topNPattern = topNPattern;
+        this.sampleLogSize = sampleLogSize;
+        if (patternStr != null)
+            this.pattern = Pattern.compile(patternStr);
+    }
+
+    @Override
+    protected String getQueryBody(String queryText) {
+        return queryText;
+    }
+
+    @Override
+    public <T> void run(Map<String, String> parameters, ActionListener<T> listener) {
+        int topNPattern = parameters.containsKey(TOP_N_PATTERN) ? getPositiveInteger(parameters, TOP_N_PATTERN) : this.topNPattern;
+        int sampleLogSize = parameters.containsKey(SAMPLE_LOG_SIZE) ? getPositiveInteger(parameters, SAMPLE_LOG_SIZE) : this.sampleLogSize;
+        Pattern pattern = parameters.containsKey(PATTERN) ? Pattern.compile(parameters.get(PATTERN)) : this.pattern;
+
+        SearchRequest searchRequest;
+        try {
+            searchRequest = buildSearchRequest(parameters);
+        } catch (Exception e) {
+            log.error("Failed to build search request.", e);
+            listener.onFailure(e);
+            return;
+        }
+
+        ActionListener<SearchResponse> actionListener = ActionListener.wrap(r -> {
+            SearchHit[] hits = r.getHits().getHits();
+
+            if (hits != null && hits.length > 0) {
+                String patternField = parameters.containsKey(PATTERN_FIELD)
+                    ? parameters.get(PATTERN_FIELD)
+                    : findLongestField(hits[0].getSourceAsMap());
+                if (patternField == null) {
+                    listener.onResponse((T) "Pattern field is not set and this index doesn't contain any string field");
+                    return;
+                }
+                Map<String, List<Map<String, Object>>> patternGroups = new HashMap<>();
+                for (SearchHit hit : hits) {
+                    Map<String, Object> source = hit.getSourceAsMap();
+                    String patternValue = extractPattern((String) source.getOrDefault(patternField, ""), pattern);
+                    List<Map<String, Object>> group = patternGroups.computeIfAbsent(patternValue, k -> new ArrayList<>());
+                    group.add(source);
+                }
+                List<Map<String, Object>> sortedEntries = patternGroups
+                    .entrySet()
+                    .stream()
+                    .sorted(Comparator.comparingInt(entry -> -entry.getValue().size()))
+                    .limit(topNPattern)
+                    .map(
+                        entry -> Map
+                            .of(
+                                "total count",
+                                entry.getValue().size(),
+                                "pattern",
+                                entry.getKey(),
+                                "sample logs",
+                                entry.getValue().subList(0, Math.min(entry.getValue().size(), sampleLogSize))
+                            )
+                    )
+                    .toList();
+
+                listener
+                    .onResponse((T) AccessController.doPrivileged((PrivilegedExceptionAction<String>) () -> gson.toJson(sortedEntries)));
+            } else {
+                listener.onResponse((T) "Can not get any match from search result.");
+            }
+        }, e -> {
+            log.error("Failed to search index.", e);
+            listener.onFailure(e);
+        });
+        client.search(searchRequest, actionListener);
+    }
+
+    /**
+     * Extract a pattern from the value of a field by removing chars in the pattern. This function
+     * imitates the same logic of Observability log pattern feature here:
+     * <a href="https://github.com/opensearch-project/sql/blob/4303a2ab755d53903094dd94a5100572677a27a1/core/src/main/java/org/opensearch/sql/expression/parse/PatternsExpression.java#L53">parseValue</a>
+     * @param rawString string value of the field to generate a pattern
+     * @param pattern @Nullable the specified pattern to remove, use DEFAULT_IGNORED_CHARS if null
+     * @return the generated pattern value
+     */
+    @VisibleForTesting
+    static String extractPattern(String rawString, Pattern pattern) {
+        if (pattern != null)
+            return pattern.matcher(rawString).replaceAll("");
+        char[] chars = rawString.toCharArray();
+        int pos = 0;
+        for (int i = 0; i < chars.length; i++) {
+            if (!DEFAULT_IGNORED_CHARS.contains(chars[i])) {
+                chars[pos++] = chars[i];
+            }
+        }
+        return new String(chars, 0, pos);
+    }
+
+    /**
+     * Find the longest field in the sample log source. This function imitates the same logic of
+     * Observability log pattern feature here:
+     * <a href="https://github.com/opensearch-project/dashboards-observability/blob/279463ad0c8e00780bf57f85e6d2bf30e8c7c93d/public/components/event_analytics/hooks/use_fetch_patterns.ts#L137C2-L164C6">setDefaultPatternsField</a>
+     * @param sampleLogSource sample log source map
+     * @return the longest field name
+     */
+    @VisibleForTesting
+    static String findLongestField(Map<String, Object> sampleLogSource) {
+        String longestField = null;
+        int maxLength = 0;
+
+        for (Map.Entry<String, Object> entry : sampleLogSource.entrySet()) {
+            Object value = entry.getValue();
+            if (value instanceof String) {
+                String stringValue = (String) value;
+                int length = stringValue.length();
+                if (length > maxLength) {
+                    maxLength = length;
+                    longestField = entry.getKey();
+                }
+            }
+        }
+        return longestField;
+    }
+
+    @Override
+    public String getType() {
+        return TYPE;
+    }
+
+    @Override
+    public boolean validate(Map<String, String> parameters) {
+        // LogPatternTool needs to pass index and input as parameter in runtime.
+        return super.validate(parameters) && parameters.containsKey(INDEX_FIELD) && !StringUtils.isBlank(parameters.get(INDEX_FIELD));
+    }
+
+    private static int getPositiveInteger(Map<String, ?> params, String paramName) {
+        int value = getInteger(params, paramName);
+        checkPositive(value, paramName);
+        return value;
+    }
+
+    private static int getInteger(Map<String, ?> params, String paramName) {
+        int value;
+        try {
+            value = Integer.parseInt((String) params.get(paramName));
+        } catch (NumberFormatException e) {
+            throw new IllegalArgumentException(
+                LoggerMessageFormat.format("Invalid value {} for parameter {}, it should be a number", params.get(paramName), paramName)
+            );
+        }
+        return value;
+    }
+
+    private static void checkPositive(int value, String paramName) {
+        if (value <= 0) {
+            throw new IllegalArgumentException(
+                LoggerMessageFormat.format("Invalid value {} for parameter {}, it should be positive", value, paramName)
+            );
+        }
+    }
+
+    public static class Factory extends AbstractRetrieverTool.Factory<LogPatternTool> {
+        private static LogPatternTool.Factory INSTANCE;
+
+        public static LogPatternTool.Factory getInstance() {
+            if (INSTANCE != null) {
+                return INSTANCE;
+            }
+            synchronized (LogPatternTool.class) {
+                if (INSTANCE != null) {
+                    return INSTANCE;
+                }
+                INSTANCE = new LogPatternTool.Factory();
+                return INSTANCE;
+            }
+        }
+
+        @Override
+        public LogPatternTool create(Map<String, Object> params) {
+            int docSize = params.containsKey(DOC_SIZE_FIELD) ? getInteger(params, DOC_SIZE_FIELD) : LOG_PATTERN_DEFAULT_DOC_SIZE;
+            int topNPattern = params.containsKey(TOP_N_PATTERN) ? getInteger(params, TOP_N_PATTERN) : DEFAULT_TOP_N_PATTERN;
+            int sampleLogSize = params.containsKey(SAMPLE_LOG_SIZE) ? getInteger(params, SAMPLE_LOG_SIZE) : DEFAULT_SAMPLE_LOG_SIZE;
+            String patternStr = params.containsKey(PATTERN) ? (String) params.get(PATTERN) : null;
+            return LogPatternTool
+                .builder()
+                .client(client)
+                .xContentRegistry(xContentRegistry)
+                .docSize(docSize)
+                .topNPattern(topNPattern)
+                .sampleLogSize(sampleLogSize)
+                .patternStr(patternStr)
+                .build();
+        }
+
+        @Override
+        public String getDefaultType() {
+            return TYPE;
+        }
+
+        @Override
+        public String getDefaultVersion() {
+            return null;
+        }
+
+        @Override
+        public String getDefaultDescription() {
+            return DEFAULT_DESCRIPTION;
+        }
+    }
+}

src/test/java/org/opensearch/agent/tools/LogPatternToolTests.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.opensearch.agent.tools;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.regex.Pattern;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import lombok.SneakyThrows;
+
+public class LogPatternToolTests {
+
+    public static final String TEST_QUERY_TEXT = "123fsd23134sdfouh";
+    private Map<String, Object> params = new HashMap<>();
+
+    @Before
+    public void setup() {}
+
+    @Test
+    @SneakyThrows
+    public void testCreateTool() {
+        LogPatternTool tool = LogPatternTool.Factory.getInstance().create(params);
+        assertEquals(LogPatternTool.LOG_PATTERN_DEFAULT_DOC_SIZE, (int) tool.docSize);
+        assertEquals(LogPatternTool.DEFAULT_TOP_N_PATTERN, tool.getTopNPattern());
+        assertEquals(LogPatternTool.DEFAULT_SAMPLE_LOG_SIZE, tool.getSampleLogSize());
+        assertNull(tool.getPattern());
+        assertEquals("LogPatternTool", tool.getType());
+        assertEquals("LogPatternTool", tool.getName());
+        assertEquals(LogPatternTool.DEFAULT_DESCRIPTION, LogPatternTool.Factory.getInstance().getDefaultDescription());
+    }
+
+    @Test
+    public void testGetQueryBody() {
+        LogPatternTool tool = LogPatternTool.Factory.getInstance().create(params);
+        assertEquals(TEST_QUERY_TEXT, tool.getQueryBody(TEST_QUERY_TEXT));
+    }
+
+    @Test
+    public void testFindLongestField() {
+        assertEquals("field2", LogPatternTool.findLongestField(Map.of("field1", "123", "field2", "1234", "filed3", 1234)));
+    }
+
+    @Test
+    public void testExtractPattern() {
+        assertEquals("././", LogPatternTool.extractPattern("123.abc/.AB/", null));
+        assertEquals("123.c/.AB/", LogPatternTool.extractPattern("123.abc/.AB/", Pattern.compile("ab")));
+        assertEquals(".abc/.AB/", LogPatternTool.extractPattern("123.abc/.AB/", Pattern.compile("[0-9]")));
+    }
+}