niels niels

Author: szybia

server/src/main/java/org/elasticsearch/cluster/metadata/LifecycleExecutionState.java

@@ -290,6 +290,8 @@ public Map<String, String> asMap() {
     /**
      * Truncates a potentially long JSON string to ensure it does not exceed {@link #MAXIMUM_STEP_INFO_STRING_LENGTH}. If truncation
      * occurs, an explanation suffix is appended to the truncated string indicating <i>approximately</i> how many characters were removed.
+     * We return an approximation because we're valuing code simplicity over accuracy in this area.
+     *
      * @param json the JSON string to potentially truncate
      * @return the original JSON string if its length is within the limit, otherwise a truncated version with an explanation suffix - in
      * correct JSON format

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ilm/LifecycleExecutionStateTests.java

@@ -15,6 +15,7 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import static org.hamcrest.Matchers.endsWith;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.hasLength;
 import static org.hamcrest.Matchers.not;
@@ -36,15 +37,8 @@ public void testTruncatingStepInfo() {
             + randomAlphanumericOfLength(LifecycleExecutionState.MAXIMUM_STEP_INFO_STRING_LENGTH + 100)
             + "\"}";
         LifecycleExecutionState newState = LifecycleExecutionState.builder(state).setStepInfo(longStepInfo).build();
-        assertThat(newState.stepInfo().length(), equalTo(LifecycleExecutionState.MAXIMUM_STEP_INFO_STRING_LENGTH));
-        assertThat(
-            newState.stepInfo()
-                .substring(
-                    LifecycleExecutionState.MAXIMUM_STEP_INFO_STRING_LENGTH - 28,
-                    LifecycleExecutionState.MAXIMUM_STEP_INFO_STRING_LENGTH
-                ),
-            equalTo("... (~111 chars truncated)\"}")
-        );
+        assertThat(newState.stepInfo(), hasLength(LifecycleExecutionState.MAXIMUM_STEP_INFO_STRING_LENGTH));
+        assertThat(newState.stepInfo(), endsWith("... (~111 chars truncated)\"}"));
     }
 
     public void testEmptyValuesAreNotSerialized() {
@@ -154,11 +148,13 @@ public void testGetCurrentStepKey() {
         assertNull(error6.getMessage());
     }
 
-    public void testPotentiallyTruncateLongJsonWithExplanationNotTruncated() {
+    /** test that strings with length less than or equal to maximum string length are not truncated and returned as-is */
+    public void testPotentiallyTruncateLongJsonWithExplanationNoNeedToTruncate() {
         final String input = randomAlphaOfLengthBetween(0, LifecycleExecutionState.MAXIMUM_STEP_INFO_STRING_LENGTH);
         assertSame(input, LifecycleExecutionState.potentiallyTruncateLongJsonWithExplanation(input));
     }
 
+    /** test that string with length one character over the max limit has truncation applied to it and has correct explanation */
     public void testPotentiallyTruncateLongJsonWithExplanationOneCharTruncated() {
         final String jsonBaseFormat = "{\"key\": \"%s\"}";
         final int baseLength = Strings.format(jsonBaseFormat, "").length();
@@ -175,6 +171,7 @@ public void testPotentiallyTruncateLongJsonWithExplanationOneCharTruncated() {
         assertEquals(expectedOutput, actualOutput);
     }
 
+    /** test that string with length two characters over the max limit has truncation applied to it and has correct explanation */
     public void testPotentiallyTruncateLongJsonWithExplanationTwoCharsTruncated() {
         final String jsonBaseFormat = "{\"key\": \"%s\"}";
         final int baseLength = Strings.format(jsonBaseFormat, "").length();

x-pack/plugin/ilm/qa/multi-node/src/javaRestTest/java/org/elasticsearch/xpack/ilm/ExplainLifecycleIT.java

@@ -320,6 +320,19 @@ public void testStepInfoPreservedOnAutoRetry() throws Exception {
         }, 30, TimeUnit.SECONDS);
     }
 
+    /**
+     * Test that, when there is an ILM <code>previous_step_info</code> that has had truncation applied to it (due to it being too long),
+     * the truncation:
+     * <ul>
+     * <li>doesn't break the JSON returned in <code>/{index}/_ilm/explain</code></li>
+     * <li>truncates as expected</li>
+     * </ul>
+     * We test this by creating an ILM policy that rolls-over at 1 document, and an index pattern that has a non-existing rollover alias
+     * that has a very long name (to trip the truncation due to the rollover alias name being in the <code>previous_step_info</code>).
+     * <p>
+     * We then index a document, wait for attempted rollover, and assert that we get valid JSON and expected truncated message
+     * in <code>/{index}/_ilm/explain</code>.
+     */
     public void testTruncatedPreviousStepInfoDoesNotBreakExplainJson() throws Exception {
         final String policyName = "policy-" + randomAlphaOfLength(5).toLowerCase(Locale.ROOT);