Share the transition attempt metadata helper

The x-amz-meta-scal-s3-transition-attempt key was open-coded in six
places across lifecycle, gc and replication, each with a slightly
different way of reading or clearing it - one of which would throw on
user metadata that does not parse. Move it behind a small helper.

Issue: BB-814

Author: francoisferrand

extensions/gc/tasks/GarbageCollectorTask.js

@@ -5,6 +5,7 @@ const { ObjectMD } = require('arsenal').models;
 const BackbeatTask = require('../../../lib/tasks/BackbeatTask');
 const { BatchDeleteCommand } = require('@scality/cloudserverclient');
 const { GarbageCollectorMetrics } = require('../GarbageCollectorMetrics');
+const { clearTransitionAttempt } = require('../../../lib/util/transitionAttempt');
 /** @typedef { import('../GarbageCollector.js') } GarbageCollector */
 
 class GarbageCollectorTask extends BackbeatTask {
@@ -290,10 +291,8 @@ class GarbageCollectorTask extends BackbeatTask {
                     .setDataStoreName(newLocation)
                     .setAmzStorageClass(newLocation)
                     .setOriginOp('s3:LifecycleTransition')
-                    .setTransitionInProgress(false)
-                    .setUserMetadata({
-                        'x-amz-meta-scal-s3-transition-attempt': undefined,
-                    });
+                    .setTransitionInProgress(false);
+                clearTransitionAttempt(objMD);
                 this._putMetadata(entry, objMD, log, err => {
                     GarbageCollectorMetrics.onS3Request(log, 'putMetadata', 'archive', err);
                     if (!err) {

extensions/lifecycle/tasks/LifecycleColdStatusArchiveTask.js

@@ -4,6 +4,7 @@ const ObjectMDArchive = require('arsenal').models.ObjectMDArchive;
 const ActionQueueEntry = require('../../../lib/models/ActionQueueEntry');
 const LifecycleUpdateTransitionTask = require('./LifecycleUpdateTransitionTask');
 const { LifecycleMetrics } = require('../LifecycleMetrics');
+const { clearTransitionAttempt } = require('../../../lib/util/transitionAttempt');
 
 class SkipMdUpdateError extends Error {}
 
@@ -115,10 +116,8 @@ class LifecycleColdStatusArchiveTask extends LifecycleUpdateTransitionTask {
                     objectMD.setDataStoreName(coldLocation)
                         .setAmzStorageClass(coldLocation)
                         .setTransitionInProgress(false)
-                        .setOriginOp('s3:LifecycleTransition')
-                        .setUserMetadata({
-                            'x-amz-meta-scal-s3-transition-attempt': undefined,
-                        });
+                        .setOriginOp('s3:LifecycleTransition');
+                    clearTransitionAttempt(objectMD);
                 }
 
                 this._putMetadata(entry, objectMD, log, err => {

extensions/lifecycle/tasks/LifecycleResetTransitionInProgressTask.js

@@ -1,6 +1,7 @@
 'use strict';
 
 const { LifecycleRequeueTask } = require('./LifecycleRequeueTask');
+const { setTransitionAttempt } = require('../../../lib/util/transitionAttempt');
 
 class LifecycleResetTransitionInProgressTask extends LifecycleRequeueTask {
     /**
@@ -19,9 +20,7 @@ class LifecycleResetTransitionInProgressTask extends LifecycleRequeueTask {
         }
         md.setOriginOp('s3:LifecycleTransition:Retry');
         md.setTransitionInProgress(false);
-        md.setUserMetadata({
-            'x-amz-meta-scal-s3-transition-attempt': try_,
-        });
+        setTransitionAttempt(md, try_);
         return true;
     }
 

extensions/lifecycle/tasks/LifecycleTask.js

@@ -24,6 +24,7 @@ const ReplicationAPI = require('../../replication/ReplicationAPI');
 const { LifecycleMetrics, LIFECYCLE_MARKER_METRICS_LOCATION } = require('../LifecycleMetrics');
 const locationsConfig = require('../../../conf/locationConfig.json') || {};
 const { rulesSupportTransition } = require('../util/rules');
+const { getTransitionAttempt } = require('../../../lib/util/transitionAttempt');
 const { stampTraceHeaders } = require('arsenal/build/lib/tracing').kafka;
 const { decode } = versioning.VersionID;
 
@@ -1176,15 +1177,7 @@ class LifecycleTask extends BackbeatTask {
     }
 
     _getTransitionActionEntry(params, objectMD, log, cb) {
-        let attempt;
-        const umd = objectMD.getUserMetadata();
-        if (umd) {
-            const parsed = JSON.parse(umd);
-            const rawAttempt = parsed['x-amz-meta-scal-s3-transition-attempt'];
-            if (rawAttempt) {
-                attempt = Number.parseInt(rawAttempt, 10);
-            }
-        }
+        const attempt = getTransitionAttempt(objectMD.getUserMetadata());
 
         const entry = ReplicationAPI.createCopyLocationAction({
             bucketName: params.bucket,

extensions/lifecycle/tasks/LifecycleUpdateTransitionTask.js

@@ -6,6 +6,11 @@ const BackbeatTask = require('../../../lib/tasks/BackbeatTask');
 const ActionQueueEntry = require('../../../lib/models/ActionQueueEntry');
 const ObjectMD = require('arsenal').models.ObjectMD;
 const { LifecycleMetrics, getCopyLocationMetricsType } = require('../LifecycleMetrics');
+const {
+    getTransitionAttempt,
+    setTransitionAttempt,
+    clearTransitionAttempt,
+} = require('../../../lib/util/transitionAttempt');
 /** @typedef { import('../objectProcessor/LifecycleObjectProcessor.js') } LifecycleObjectProcessor */
 
 class LifecycleUpdateTransitionTask extends BackbeatTask {
@@ -71,10 +76,8 @@ class LifecycleUpdateTransitionTask extends BackbeatTask {
             .setDataStoreName(newLocationName)
             .setAmzStorageClass(newLocationName)
             .setOriginOp('s3:LifecycleTransition')
-            .setUserMetadata({
-                'x-amz-meta-scal-s3-transition-attempt': undefined,
-            })
             .setTransitionInProgress(false);
+        clearTransitionAttempt(objMD);
     }
 
     _putMetadata(entry, objMD, log, done) {
@@ -232,20 +235,10 @@ class LifecycleUpdateTransitionTask extends BackbeatTask {
                 next(err, objMD);
             }),
             (objMD, next) => {
-                const userMDStr = objMD.getUserMetadata() || '{}';
-                const userMD = JSON.parse(userMDStr);
+                const tryCount = (getTransitionAttempt(objMD.getUserMetadata()) || 0) + 1;
 
-                let tryCount = userMD['x-amz-meta-scal-s3-transition-attempt'];
-                if (tryCount === undefined) {
-                    tryCount = 1;
-                } else {
-                    tryCount = parseInt(tryCount, 10) + 1;
-                }
-
-                objMD.setTransitionInProgress(false)
-                    .setUserMetadata({
-                        'x-amz-meta-scal-s3-transition-attempt': tryCount,
-                    });
+                objMD.setTransitionInProgress(false);
+                setTransitionAttempt(objMD, tryCount);
 
                 return this._putMetadata(entry, objMD, log, next);
             },

extensions/replication/ReplicationQueuePopulator.js

@@ -10,9 +10,9 @@ const { LifecycleMetrics, LOCALIZATION_TYPE } = require('../lifecycle/LifecycleM
 const config = require('../../lib/Config');
 const locationsConfig = require('../../conf/locationConfig.json') || {};
 const safeJsonParse = require('../../lib/util/safeJsonParse');
+const { getTransitionAttempt } = require('../../lib/util/transitionAttempt');
 const { traceHeadersFromEntry } = require('arsenal/build/lib/tracing').kafka;
 
-const TRANSITION_ATTEMPT_MD = 'x-amz-meta-scal-s3-transition-attempt';
 const { transitionTasksTopic } = config.extensions.lifecycle;
 
 // Where clean room objects are localized when their metadata does not name a
@@ -202,7 +202,7 @@ class ReplicationQueuePopulator extends QueuePopulatorExtension {
             contentLength,
             resultsTopic: transitionTasksTopic,
             transitionTime: transitionTime.toISOString(),
-            attempt: this._getTransitionAttempt(queueEntry),
+            attempt: getTransitionAttempt(queueEntry.getUserMetadata()),
         });
         // 'transition' is what the lifecycle transition processor dispatches
         // on to pick up the copyLocation result.
@@ -269,26 +269,6 @@ class ReplicationQueuePopulator extends QueuePopulatorExtension {
         return defaultLocalLocation;
     }
 
-    /**
-     * Number of times the data mover already tried to copy this object. The
-     * transition processor bumps the counter on failure, which produces a new
-     * oplog entry and re-triggers the copy.
-     * @param {ObjectQueueEntry} queueEntry - parsed entry
-     * @return {Number|undefined} attempt count, if any
-     */
-    _getTransitionAttempt(queueEntry) {
-        const umd = queueEntry.getUserMetadata();
-        if (!umd) {
-            return undefined;
-        }
-        const { error, result } = safeJsonParse(umd);
-        if (error) {
-            return undefined;
-        }
-        const attempt = Number.parseInt(result[TRANSITION_ATTEMPT_MD], 10);
-        return Number.isInteger(attempt) ? attempt : undefined;
-    }
-
     /**
      * Filter if the entry is considered a valid master key entry.
      * There is a case where a single null entry looks like a master key and

lib/util/transitionAttempt.js

@@ -0,0 +1,52 @@
+const safeJsonParse = require('./safeJsonParse');
+
+// How many times the transition of an object was attempted. Kept in the
+// object user metadata so that it survives across processes: the transition
+// processor bumps it on failure, and it is cleared once the object made it to
+// its new location.
+const TRANSITION_ATTEMPT_MD = 'x-amz-meta-scal-s3-transition-attempt';
+
+/**
+ * Read the transition attempt count from raw object user metadata.
+ * @param {String|undefined} userMetadata - serialized user metadata, as
+ * returned by ObjectMD.getUserMetadata()
+ * @return {Number|undefined} attempt count, or undefined if the object was
+ * never transitioned, or the metadata cannot be read
+ */
+function getTransitionAttempt(userMetadata) {
+    if (!userMetadata) {
+        return undefined;
+    }
+    const { error, result } = safeJsonParse(userMetadata);
+    if (error) {
+        return undefined;
+    }
+    const attempt = Number.parseInt(result[TRANSITION_ATTEMPT_MD], 10);
+    return Number.isInteger(attempt) ? attempt : undefined;
+}
+
+/**
+ * Set the transition attempt count on an object.
+ * @param {ObjectMD} objMD - object metadata to update in place
+ * @param {Number} attempt - attempt count
+ * @return {ObjectMD} the updated object metadata
+ */
+function setTransitionAttempt(objMD, attempt) {
+    return objMD.setUserMetadata({ [TRANSITION_ATTEMPT_MD]: attempt });
+}
+
+/**
+ * Forget the transition attempt count, once the transition succeeded.
+ * @param {ObjectMD} objMD - object metadata to update in place
+ * @return {ObjectMD} the updated object metadata
+ */
+function clearTransitionAttempt(objMD) {
+    return setTransitionAttempt(objMD, undefined);
+}
+
+module.exports = {
+    TRANSITION_ATTEMPT_MD,
+    getTransitionAttempt,
+    setTransitionAttempt,
+    clearTransitionAttempt,
+};