diff options
Diffstat (limited to 'configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializer.java')
| -rw-r--r-- | configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializer.java | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializer.java b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializer.java index 379af7f71ea..91f9e3c8eed 100644 --- a/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializer.java +++ b/configserver/src/main/java/com/yahoo/vespa/config/server/tenant/ContainerEndpointSerializer.java @@ -18,6 +18,13 @@ import java.util.List; */ public class ContainerEndpointSerializer { + // WARNING: Since there are multiple servers in a ZooKeeper cluster and they upgrade one by one + // (and rewrite all nodes on startup), changes to the serialized format must be made + // such that what is serialized on version N+1 can be read by version N: + // - ADDING FIELDS: Always ok + // - REMOVING FIELDS: Stop reading the field first. Stop writing it on a later version. + // - CHANGING THE FORMAT OF A FIELD: Don't do it bro. + private static final String clusterIdField = "clusterId"; private static final String namesField = "names"; |