Upgrading from 0.8 to 0.9

0.9.0 is a major upgrade with breaking changes to the data format, the wire protocol and the server configuration. Work through this list before moving an existing deployment. The 0.9.0 release post has the full list of changes.

Start from a fresh data directory

The on-disk format changed, and 0.9.0 can't read a data directory written by 0.8. There is no migration. Copy out anything you need to keep before switching over, then start 0.9.0 with an empty data directory.

Upgrade the server and every SDK together

0.8 clients can't talk to a 0.9.0 server, and 0.9 clients can't talk to a 0.8 server. There is no fallback between the two protocols, so plan a cutover where the server and all your clients change at the same time, rather than a rolling upgrade.

Check Server compatibility for the SDK version that goes with the 0.9.0 server in each language.

Review your configuration

Don't carry the old config.toml or IGGY_* environment variables across unchanged. The server refuses to start if it finds a setting that has moved or been removed.

• The [system] table is gone. Its path key and the tables under it (runtime, logging, encryption, partition, sharding and memory_pool) move to the top level of the config. Environment variables lose SYSTEM_, so IGGY_SYSTEM_PATH becomes IGGY_PATH.
• The [stream] and [topic] tables are gone. Settings like segment_size, messages_required_to_save and size_of_messages_required_to_save are now set per topic when the topic is created. See Topic options.
• enforce_fsync and consumer_offset_enforce_fsync are gone. Durability is now chosen per topic, with durability and consumer_offset_durability. See Durability.
• The [cluster] and sharding sections were reworked. Compare yours with Configuration.

Set an advertised address when listening on all interfaces

If a listener binds to a wildcard address such as 0.0.0.0, the server now needs an advertised address too, set with IGGY_NODE_ADVERTISED_ADDRESS or node.advertised_address. 0.8 allowed a wildcard bind without one; 0.9.0 won't start. This affects most Docker deployments. See Docker & Helm.

If you build connectors in Rust

In the connector SDK, ConnectivityConfig is replaced by RetryPolicy. This only affects Rust code written against the SDK. Connector plugins that are already built are unaffected.