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author | Harald Musum <musum@verizonmedia.com> | 2019-06-16 16:31:13 +0200 |
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committer | GitHub <noreply@github.com> | 2019-06-16 16:31:13 +0200 |
commit | e70699d0afc96eff24de38aafed73f67b0c5690f (patch) | |
tree | da58331a0c8e489cc09a8d95a10bd6ff782d89c4 /config-provisioning | |
parent | 56d4744194e2684077b9585780e65a6912bf181d (diff) | |
parent | 0cf99d39c5fe547bda186112f9d7e2924305d45c (diff) |
Merge pull request #9817 from vespa-engine/bratseth/serialization-warning
Bratseth/serialization warning
Diffstat (limited to 'config-provisioning')
-rw-r--r-- | config-provisioning/src/main/java/com/yahoo/config/provision/AllocatedHosts.java | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/config-provisioning/src/main/java/com/yahoo/config/provision/AllocatedHosts.java b/config-provisioning/src/main/java/com/yahoo/config/provision/AllocatedHosts.java index de4f3a555bd..96942c53a12 100644 --- a/config-provisioning/src/main/java/com/yahoo/config/provision/AllocatedHosts.java +++ b/config-provisioning/src/main/java/com/yahoo/config/provision/AllocatedHosts.java @@ -26,6 +26,13 @@ import java.util.Set; */ public class AllocatedHosts { + // 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 mappingKey = "mapping"; private static final String hostSpecKey = "hostSpec"; private static final String hostSpecHostNameKey = "hostName"; |