Feature: dedicated peer slots for light clients

[veox]

Geth/v1.7.3-stable-4bb3c89d/linux-amd64/go1.9

I've recently spun up a node with the sole intent to serve light clients. In the systemd service file, I've indicated:

--maxpeers 150 --lightserv 90 --lightpeers 135

Of course, This doesn't do what I'd like. My peer list is 85 "light" clients and 65 "regular" ones. I'd like it to be 135/15, respectively.

It "would be nice" to have an option to limit "regular" peers; alternatively, it "would be nice" to be able to reserve peer slots specifically for "light" clients.

---

EDIT: For ref, this has been implemented in PR #16010.

[veox]

This doesn't seem particularly difficult, so could submit PR, even if it takes me a while.

This block puts a lower limit on "regular" peers, to be 1/2 of maxpeers.

---

What would be a reasonable approach and option name?

• Limit "regular" peers with --maxfullpeers? Or name it --fullpeers? --heavypeers?..
• Rework --lightpeers to mean "dedicated light client slots"?
• Allow specifying --minfullpeers?
• Something else?

[ligi]

I've recently spun up a node with the sole intent to serve light clients.

❤️ 👍 🎆 🎉 🎈 💯 🥇

[veox]

My peer list is 85 "light" clients and 65 "regular" ones.

To clarify: this is 5-15 minutes after node restart.

I've noticed that after a few days of continuous operation at the limit of the system's CPU load capacity, the numbers gravitate towards: less "regular" peers, more light ones.

At some point, though, the node experiences some failure and stops syncing (while still having both types of peers). I'll see what running at increased verbosity gets me.

---

EDIT: May be same as issue #15636.

[lmars]

I'm having a similar issue whereby I am running a light server but I actually get too many light clients (see #15689), which means I end up with only light peers and no full peers to get new blocks from.

[veox]

From #15689 (comment), --lightpeers is planned to mean "dedicated light peer connection slots".

Closing this, as it's now a duplicate (sort of).