metrics: add separate statesync and blocksync metrics

[cmwaters]

Statesync and blocksync metrics were previously housed within the consensus metrics. There were some comments that this was messy. Metrics should reside in the component that controls them. This PR separates them out into their respective packages.

[thanethomson]

There were some comments that this was messy.

Were these comments in synchronous discussions, or are they in an issue somewhere?

Also, this changes the metric labels from block_syncing -> blocksync_syncing and state_syncing -> statesync_syncing, right?

Do we anticipate that there'll be more metrics added in the blocksync_ and statesync_ groups in the v0.38 release? If not, then I'd advocate for keeping the metric labels the same. Every such change introduces friction into an upgrade, and I'd say we should keep upgrade friction at a minimum.

[thanethomson]

If not, then I'd advocate for keeping the metric labels the same.

Actually, I take this back. If we break this once then we can roll out additional metrics in an additive, non-breaking way in patch releases. Please add a changelog and/or upgrading guide entry for this though?

[cmwaters]

Were these comments in synchronous discussions, or are they in an issue somewhere?

Some synchronous but mostly in code:

tendermint/node/node.go

Line 258 in ffae184

// FIXME We need to update metrics here, since other reactors don't have access to them.

tendermint/node/setup.go

Line 578 in ffae184

// FIXME Very ugly to have these metrics bleed through here.

Do we anticipate that there'll be more metrics added in the blocksync_ and statesync_ groups in the v0.38 release?

I can imagine that there would eventually be more metrics. Tracking the amount of snapshots available in the network or the latest height blocksynced etc.

Please add a changelog and/or upgrading guide entry for this though?

Sure