Conflux v2.1.0

This release introduces a new hardfork. All nodes should be upgraded before the epoch number reaches 56800000 (estimated on Oct 18). Most CIPs will be enabled when the block number reaches 133800000 (estimated on Oct 25), and CIP-99 will be enabled when the PoS block number reaches 330000 (estimated on Oct 25).

Incompatible Changes

• CIP-94 (https://github.com/Conflux-Chain/CIPs/blob/master/CIPs/cip-94.md): This CIP proposes to use on-chain DAO voting to decide and update reward parameters without hardfork.
• CIP-97 (https://github.com/Conflux-Chain/CIPs/blob/master/CIPs/cip-97.md): This CIP proposes to remove account’s staking lists.
• CIP-98 (https://github.com/Conflux-Chain/CIPs/blob/master/CIPs/cip-98.md): Fix a bug in BLOCKHASH opcode in eSpace.
• CIP-99 (https://github.com/Conflux-Chain/CIPs/blob/master/CIPs/cip-99.md): Allow more not-voting terms before we force-retire a node, and make the unlock period of a retiring node shorter to allow the node to rejoin the PoS voting faster.
• CIP105 (https://github.com/Conflux-Chain/CIPs/blob/master/CIPs/cip-105.md): PoS staking based minimal DAO vote count.

Configuration Improvement

• Add configuration enable_single_mpt_storage to enable storing all history states. Set single_mpt_space = "evm" to only store eSpace states. Note that you'll need to resync an archive node to reconstruct all the history states.

Storage Improvement

• Allow snapshots to be removed during recovery. This reduces the disk space requirement for full node sync or recovery.

RPC Improvement

• Support eth_subscribe and eth_unsubscribe in eSpace RPCs.
• Add a RPC method cfx_getParamsFromVote to return the currently used value of the voted parameters.
• Return null for getting skipped transactions and receipts. Whether they will be returned was nondeterministic before, but now they are ensured to be null.
• When querying logs, use LatestState instead of the to epoch number when the to epoch number is greater than LatestState.

Transaction Pool Improvement

• Fix an issue that may fail to recycle packed but skipped transactions.