Limit the details field length we store for each SLM invocation

docs/changelog/97038.yaml

@@ -0,0 +1,6 @@
+pr: 97038
+summary: Limit the details field length we store for each SLM invocation
+area: ILM+SLM
+type: bug
+issues:
+ - 96918

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/slm/SnapshotInvocationRecord.java

@@ -8,6 +8,7 @@
 package org.elasticsearch.xpack.core.slm;
 
 import org.elasticsearch.cluster.SimpleDiffable;
+import org.elasticsearch.common.Strings;
 import org.elasticsearch.common.io.stream.StreamInput;
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.common.io.stream.Writeable;
@@ -31,6 +32,7 @@ public class SnapshotInvocationRecord implements SimpleDiffable<SnapshotInvocati
  static final ParseField START_TIMESTAMP = new ParseField("start_time");
  static final ParseField TIMESTAMP = new ParseField("time");
  static final ParseField DETAILS = new ParseField("details");
+ static final int MAX_DETAILS_LENGTH = 1000;
 
  private final String snapshotName;
  private final Long snapshotStartTimestamp;
@@ -54,11 +56,16 @@ public static SnapshotInvocationRecord parse(XContentParser parser, String name)
  return PARSER.apply(parser, name);
  }
 
- public SnapshotInvocationRecord(String snapshotName, Long snapshotStartTimestamp, long snapshotFinishTimestamp, String details) {
+ public SnapshotInvocationRecord(
+ String snapshotName,
+ Long snapshotStartTimestamp,
+ long snapshotFinishTimestamp,
+ @Nullable String details
+ ) {
  this.snapshotName = Objects.requireNonNull(snapshotName, "snapshot name must be provided");
  this.snapshotStartTimestamp = snapshotStartTimestamp;
  this.snapshotFinishTimestamp = snapshotFinishTimestamp;
- this.details = details;
+ this.details = Strings.substring(details, 0, MAX_DETAILS_LENGTH);
  }
 
  public SnapshotInvocationRecord(StreamInput in) throws IOException {

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/slm/SnapshotInvocationRecordTests.java

@@ -14,6 +14,9 @@
 
 import java.io.IOException;
 
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+
 public class SnapshotInvocationRecordTests extends AbstractXContentSerializingTestCase<SnapshotInvocationRecord> {
 
  @Override
@@ -56,6 +59,42 @@ protected SnapshotInvocationRecord mutateInstance(SnapshotInvocationRecord insta
  }
  }
 
+ public void testDetailsFieldIsTruncated() {
+ {
+ // value larger than the max allowed
+ SnapshotInvocationRecord snapshotInvocationRecord = new SnapshotInvocationRecord(
+ randomAlphaOfLengthBetween(5, 10),
+ randomNonNegativeNullableLong(),
+ randomNonNegativeLong(),
+ randomAlphaOfLengthBetween(1300, 1500)
+ );
+ assertThat(snapshotInvocationRecord.getDetails().length(), is(SnapshotInvocationRecord.MAX_DETAILS_LENGTH));
+ }
+
+ {
+ // value lower than the max allowed
+ String details = randomAlphaOfLengthBetween(5, 500);
+ SnapshotInvocationRecord snapshotInvocationRecord = new SnapshotInvocationRecord(
+ randomAlphaOfLengthBetween(5, 10),
+ randomNonNegativeNullableLong(),
+ randomNonNegativeLong(),
+ details
+ );
+ assertThat(snapshotInvocationRecord.getDetails().length(), is(details.length()));
+ }
+
+ {
+ // null value, remains null
+ SnapshotInvocationRecord snapshotInvocationRecord = new SnapshotInvocationRecord(
+ randomAlphaOfLengthBetween(5, 10),
+ randomNonNegativeNullableLong(),
+ randomNonNegativeLong(),
+ null
+ );
+ assertThat(snapshotInvocationRecord.getDetails(), is(nullValue()));
+ }
+ }
+
  public static SnapshotInvocationRecord randomSnapshotInvocationRecord() {
  return new SnapshotInvocationRecord(
  randomAlphaOfLengthBetween(5, 10),