Release 0.18 brings several major improvements to Blockstack Core. It is not a consensus-breaking release. 0.18.x nodes will continue to agree with 0.17.x nodes about the chain state.
However, 0.18 is a network-breaking release. In 0.18, a zone file can be 40kb, which is 10x larger than the maximum zone file size in 0.17. Large zone files announced to 0.18 will not be discovered by 0.17 nodes. As such, all node operators are encouraged to upgrade to 0.18 as soon as possible.
Server-side Subdomain Indexing: This release makes it so the
blockstack-core daemon eagerly indexes subdomain records found in zone files.
Name lookups and address lookups will return information for subdomains as well
as names. The blockstack_client library will no longer be responsible for
maintaining subdomain state of its own.
Any Name can Update a Subdomain: Any name can send out a subdomain update record for a given subdomain. It is no longer limited to the name that created it. However, subdomain transfers must be processed by the name that created them for the time being.
10x Zone File Size Increase: The 0.18 Atlas network allows a maximum zone file size of 40kb. This allows between 100 and 120 subdomains to be created in a single transaction.
New Subdomain Registrar: This version of the software ships with a new subdomain registrar designed to take advantage of the above.
Legacy Python Storage API Deprecation: This release deprecates the /v1/store API routes
in blockstack api in favor of Gaia hubs. Gaia hubs are accessed directly by
blockstack.js via HTTP(S), and employ storage drivers to
communicate with non-HTTP data sources. This was introduced in 0.16, and going
forward, will be the only supported way for reading and writing Blockstack app data.
The legacy Python API will be removed in the next release.
Improved chain-state database: The virtualchain package has changed the way it represents its consensus hashes and accepted transactions on disk. The changes make certain queries much more efficient, such as name history queries. In addition, it makes block processing somewhat faster, and makes it easier to add more opcodes in a future release. It removes a lot of complexity from Blockstack Core's consensus code.
The recommended way to get started with 0.18 is through its fast-sync mode. To migrate from a 0.17 node to a 0.18 node, we recommend the following steps:
# stop the old node
$ blockstack-core stop
$ mv ~/.blockstack-server ~/.blockstack-server.0.17
# start the new node
$ blockstack-core fast-sync
$ blockstack-core start
The old chain state database directory structure has changed, and is
incompatible with this new release. If you are
upgrading from a 0.17 node or older, you will need to remove your .blockstack-server
directory.