LoyceV's 0.1 sat/vbyte Electrum Server Adventure

[joker_josue]

But, in short, is it possible for me to choose 3 or 4 different servers, to all be connected to Electrum?

No, just one, let's say "main server" of your choice.
The rest (peers) are just for security purposes since you can't just trust that a random public server is giving you accurate information.
And those don't have access to your wallet's addresses so it's not bad to keep it randomized.

I don't think that's possible. I'm okay with "Manual server selection": it only connects to my own server, but when my server has a problem, Electrum tells me it's lagging or offline. So if you want to use a few selected servers, I'd say pick one, and switch when there's a problem.

I think this option would be a good addition to Electrum, allowing people to configure up to 10 servers of their choice.

This allowed users to choose their preferred servers. For example, some forum members could share their servers, and anyone who wanted could use them, and Electrum would automatically manage them based on performance at the time of use.

Any server has its own set of updates/maintenances and may even experience slowdowns. If Electrum has a list of servers I prefer to use, it will manage this better.

[LoyceV]

I'm thinking of switching to VPS 1000 G11 or VPS 2000 G11 which will be better for this operation.

Netcup is the best value I've found. I'm looking for more consistent service because I don't want to keep jumping from one service to another and want something that lasts longer.

I found a tempting offer for dedicated servers on Lowendtalk. CPUs aren't the most modern, and some have HDD, but I think the prices are quite good for dedicated servers. Note: I have no experience with this webhost.

[joker_josue]

I'm thinking of switching to VPS 1000 G11 or VPS 2000 G11 which will be better for this operation.

Netcup is the best value I've found. I'm looking for more consistent service because I don't want to keep jumping from one service to another and want something that lasts longer.

I found a tempting offer for dedicated servers on Lowendtalk. CPUs aren't the most modern, and some have HDD, but I think the prices are quite good for dedicated servers. Note: I have no experience with this webhost.

Look, the offer doesn't seem bad to me at all.

Even on HDD disk, considering that I already have node on my PC, it doesn't take long to synchronize. Then on a day-to-day basis it is enough.

I will analyze it to see if it is feasible for what I want. Thanks for the tip.

[LoyceV]

Most of the time, Fulcrum and Bitcoin Core use around 20% CPU each:

Code:

    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND 
3795863 electrum  20   0   45.0g   4.6g   2.6g S  28.9  14.8     59,50 bitcoind
1533471 electrum  20   0 5698884 892848  10880 S  19.3   2.7     54,39 Fulcrum 

Current stats:

Code:

    "clients_connected": 257,
    "clients_connected_max_lifetime": 334,
    "clients_connected_total_lifetime": 722989,

    "txs_sent": 419,
    "txs_sent_bytes": 384067,
    "uptime": "16.76 days",

[LoyceV]

Bump with new stats:

Code:

    "clients_connected": 281,
    "clients_connected_max_lifetime": 336,
    "clients_connected_total_lifetime": 1035666,

    "txs_sent": 628,
    "txs_sent_bytes": 519019,
    "uptime": "23.78 days",
    "utxoset": {
        "size": 168193679,
        "size_MB": 14128.27

[Abdussamad]

Electrum tries to connect to multiple servers. If you go to tools > network > server tab you will see it in the "status" section. It has this to say about it:

In addition to your history server, Electrum will try to maintain connections with ~10 extra servers, in order to download block headers and find out the longest blockchain. These servers are only used for block header notifications and fee estimates; they do not learn your wallet addresses. Getting block headers from multiple sources is useful to detect lagging servers and forks. Fork detection is security-critical for determining number of confirmations.

[joker_josue]

Electrum tries to connect to multiple servers. If you go to tools > network > server tab you will see it in the "status" section. It has this to say about it:

In addition to your history server, Electrum will try to maintain connections with ~10 extra servers, in order to download block headers and find out the longest blockchain. These servers are only used for block header notifications and fee estimates; they do not learn your wallet addresses. Getting block headers from multiple sources is useful to detect lagging servers and forks. Fork detection is security-critical for determining number of confirmations.

That's why I think it should be possible to choose more than one server manually.
At the moment it only allows you to choose a server manually, or let it randomly choose these 10 servers.

I think this would be a good addition to Electrum.

[LoyceV]

I think this would be a good addition to Electrum.

I think so too! But ThomasV isn't very active here to read it.

[Stalker22]

Electrum tries to connect to multiple servers. If you go to tools > network > server tab you will see it in the "status" section. It has this to say about it:

In addition to your history server, Electrum will try to maintain connections with ~10 extra servers, in order to download block headers and find out the longest blockchain. These servers are only used for block header notifications and fee estimates; they do not learn your wallet addresses. Getting block headers from multiple sources is useful to detect lagging servers and forks. Fork detection is security-critical for determining number of confirmations.

That's why I think it should be possible to choose more than one server manually.
At the moment it only allows you to choose a server manually, or let it randomly choose these 10 servers.

I think this would be a good addition to Electrum.

But even if you manually select a server, the Electrum client still connects to ten other nodes.  This is likely a security feature, as the client is designed to use multiple servers to verify that the block headers are correct and protect against malicious actors and forks.

[Cricktor]

In addition to your history server, Electrum will try to maintain connections with ~10 extra servers, in order to download block headers and find out the longest blockchain. These servers are only used for block header notifications and fee estimates; they do not learn your wallet addresses. Getting block headers from multiple sources is useful to detect lagging servers and forks. Fork detection is security-critical for determining number of confirmations.

Interesting, indeed, especially the part I highlighted! My question to someone (or one of the devs) fluent enough with Electrum's code is: does the command-line option  --server server:port:t|s  pin the history server and make any other additional server which Electrum chooses automatically the ones that are only used for new block header announcements and which according to above's quotation don't get to know an Electrum wallet's addresses?

If this were the case, I could and would use my personal Electrum server as my history server (I do that already but I use the option --oneserver which limits Electrum to use solely the specified server). This wouldn't leak my wallet's addresses to some unknown Electrum server.

[LoyceV]

I noticed my Electrum was offline. On my server:

Code:

FulcrumAdmin getinfo
    timed out

It looks like this is caused by high load (caused by my Trust list viewer update), which sometimes leads to CPU steal. That shouldn't happen, but it happens nonetheless. Electrum is back online now, and it was the first time I noticed. I'll keep an eye on it.

[Pmalek]

I think so too! But ThomasV isn't very active here to read it.

ThomasV is inactive, but ghost43, aka Electrum developer SomberNight is active from time to time. He writes exclusively in topics that are about Electrum. I am sure he would forward to ThomasV or consider anything that is worthwhile to add to Electrum if he saw it or if he was asked about it. I doubt he uses any of the notification bots to notice he was mentioned, though.

[LoyceV]

Shower thought (bear with me): you could run your own Electrum server locally, have it completely synced, backup all data on an external disk, remove it's internet cable (don't give it Wifi),  and load a cold Electrum wallet. That allows you to view the balance on all your addresses, and you can even sign transactions without needing a watch-only hot wallet. After you're done, properly wipe the system and your keys stay offline. Next time you need it, restore your backup from the external disk, let it finish syncing, and take it offline again.
End of shower thought I haven't tried this yet.

[joker_josue]

Shower thought (bear with me): you could run your own Electrum server locally, have it completely synced, backup all data on an external disk, remove it's internet cable (don't give it Wifi),  and load a cold Electrum wallet. That allows you to view the balance on all your addresses, and you can even sign transactions without needing a watch-only hot wallet. After you're done, properly wipe the system and your keys stay offline. Next time you need it, restore your backup from the external disk, let it finish syncing, and take it offline again.
End of shower thought I haven't tried this yet.

But to carry out the transaction, once signed, he had to put the system online.
Doing so required keeping the wallet on. Or not?
I understand the idea, but only in a visualization, for movement I am not seeing as an employee.

[LoyceV]

But to carry out the transaction, once signed, he had to put the system online.

I forgot that part: just copy the signed transaction to an USB stick, and broadcast it from another system.

[joker_josue]

But to carry out the transaction, once signed, he had to put the system online.

I forgot that part: just copy the signed transaction to an USB stick, and broadcast it from another system.

But still won't you need the "key"?

Basically, it was just to prevent the main wallet from ever being exposed to the web.

[LoyceV]

But still won't you need the "key"?

You'll have the key on the offline system (until you wipe it).

Stats!

Code:

    "clients_connected": 359,
    "clients_connected_max_lifetime": 436,
    "clients_connected_total_lifetime": 4992479,

    "txs_sent": 4037,
    "txs_sent_bytes": 3591505,
    "uptime": "3.238 months",

When I started my Electrum server, I never expected it to be used this much! That's about 40 transactions per day on average.