MAILBOX-339 Rolling migration for mailboxPathV2

apache · May 28, 2018 · 7b38d06 · 7b38d06
1 parent 9a515e0
commit 7b38d06
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Showing 2 changed files with 24 additions and 4 deletions.
diff --git a/...ssandra/src/main/java/org/apache/james/mailbox/cassandra/mail/CassandraMailboxMapper.java b/...ssandra/src/main/java/org/apache/james/mailbox/cassandra/mail/CassandraMailboxMapper.java
@@ -26,6 +26,7 @@
 import java.util.StringTokenizer;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
+import java.util.concurrent.CompletionStage;
 import java.util.function.Function;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
@@ -108,12 +109,30 @@ private CompletableFuture<Optional<SimpleMailbox>> fromPreviousTable(MailboxPath
                     cassandraIdOptional
                         .map(CassandraIdAndPath::getCassandraId)
                         .map(this::retrieveMailbox)
-                        .orElse(CompletableFuture.completedFuture(Optional.empty())));
+                        .orElse(CompletableFuture.completedFuture(Optional.empty())))
+                .thenCompose(maybeMailbox -> maybeMailbox.map(this::migrate)
+                    .orElse(CompletableFuture.completedFuture(maybeMailbox)));
         } catch (CompletionException e) {
             throw DriverExceptionHelper.handleStorageException(e);
         }
     }
 
+    private CompletableFuture<Optional<SimpleMailbox>> migrate(SimpleMailbox mailbox) {
+        CassandraId mailboxId = (CassandraId) mailbox.getMailboxId();
+        return mailboxPathV2DAO.save(mailbox.generateAssociatedPath(), mailboxId)
+            .thenCompose(success -> deleteIfSuccess(mailbox, success))
+            .thenApply(any -> Optional.of(mailbox));
+    }
+
+    private CompletionStage<Void> deleteIfSuccess(SimpleMailbox mailbox, boolean success) {
+        if (success) {
+            return mailboxPathDAO.delete(mailbox.generateAssociatedPath());
+        }
+        LOGGER.info("Concurrent execution lead to data race while migrating {} to 'mailboxPathV2DAO'.",
+            mailbox.generateAssociatedPath());
+        return CompletableFuture.completedFuture(null);
+    }
+
     @Override
     public Mailbox findMailboxById(MailboxId id) throws MailboxException {
         CassandraId mailboxId = (CassandraId) id;

diff --git a/...st/java/org/apache/james/mailbox/cassandra/mail/migration/MailboxPathV2MigrationTest.java b/...st/java/org/apache/james/mailbox/cassandra/mail/migration/MailboxPathV2MigrationTest.java
@@ -108,15 +108,16 @@ public void newValuesShouldNotBeSavedInOldDAO() throws Exception {
     }
 
     @Test
-    public void readingOldValuesShouldNotMigrateThem() throws Exception {
+    public void readingOldValuesShouldMigrateThem() throws Exception {
         daoV1.save(MAILBOX_PATH_1, MAILBOX_ID_1).join();
         mailboxDAO.save(MAILBOX_1).join();
 
         mailboxMapper.findMailboxByPath(MAILBOX_PATH_1);
 
         SoftAssertions softly = new SoftAssertions();
-        softly.assertThat(daoV1.retrieveId(MAILBOX_PATH_1).join()).isNotEmpty();
+        softly.assertThat(daoV1.retrieveId(MAILBOX_PATH_1).join()).isEmpty();
-        softly.assertThat(daoV2.retrieveId(MAILBOX_PATH_1).join()).isEmpty();
+        softly.assertThat(daoV2.retrieveId(MAILBOX_PATH_1).join())
+            .contains(new CassandraIdAndPath(MAILBOX_ID_1, MAILBOX_PATH_1));
         softly.assertAll();
     }