A lot of the alt coins have got very sick indeed recently. Whether it's the recent run up in BTC price, or something else, I don't know.

For example, I have been mining CSC as a backup for when middlecoin goes down, if I don't want to mine on the EU server. Yet, something has happened to cut the CSC/BTC exchange in half today.  Lots of other alt coins showing long slow crashes in price too.

The US server is a bit happier than it has been, but that seems to be a reflection of the coin situation. Over the last few days, there has been massive fluctuation in difficulty and value of many alts, causing lots of crazy switching from one coin to another.

I don't think the server bug is that high of a priority at the moment, because of the change in coin situation.

However, I would like to make the suggestion that H2O offers an "experimental" server. This could run the most recent test version of the pool, and people could try hashing on it, for a "real world" test of whether the fix is helping or not.

Finally, I came across something very concerning regarding middlecoin. I was testing a new Wifi connection from a local provider (as a backup to wired connecrtivity). It turns out that they block middlecoin - if you try to access the web page, you just get a message - "This site has been blocked. Reason: Contains images of child abuse, or links to child abuse/pornography". I tested access to the pool ports, and they were all blocked as well. I'm guessing that this is a false positive. However, I did call the wifi provider's tech support to ask, and they said, they simply said that they can't unblock it because of illegal material.

The problem seems to be that some overaggressive filter is finding something it doesn't like. I wonder if maybe one of the bitcoin addresses in the list has been implicated in something illegal. Perhaps there might be some benefit in part censoring the addresses, or purging idle addresses from the default list.

I don't know if coin switching alone will account for the rejects. From what I have seen, when the coin changes, cgminer simply discards the work it was doing, and doesn't count it as a reject.

Rejects tend to occur when the work is received too late. I find that this happens most often when mining very "fast" coins. Mining litecoin, which has a 2.5 minute block time, I get about 3% rejects, mining DOGE with a 1 minute block, I get about 4%, for something like casinocoin with a 30 sec block, I get about 7%, and for something like fastcoin, I get over 20% rejects. A slow or laggy internet connection (e.g. a 3G connection, which frequently has a ping time in the 2000 ms range) can make this problem a lot worse.

The same problem can occur when a huge pool switches onto a small coin, and the block rates go way out of spec before the difficulty readjusts.

I haven't noticed middlecoin mining any very fast or very small coins. At the moment its flip-flopping between litecoin, dogecoin and megacoin every few seconds, but I'm not getting more rejects that I normally get. However, my miners keep failing over onto the EU server several times per hour, presumably because there are too many coin switches and disconnects.

Every time the coin switches, cgminer will pause for a few seconds and discard the work it was doing on the old coin, so those hashes don't get counted.

There is also the issue that the stratum mining protocol isn't set up for changing coins on the same pool. The pool has to reset the connection, and cgminer sees this as a network problem, and will stop mining, or change to another pool.

The problem is that middlecoin is changing coin every 30-45 seconds, so when cgminer goes idle for 5 seconds after a coin change, it makes a big overall impact.



You can see this happening in this monitor screenshot from my mines. The orange hash rate charts are middlecoin, and you can see the pauses every time the coin changes. For comparison the blue and red charts are different pools, and you can see the highly consistent hashrates. You can also see how the coin change affects all the mines simultaneously.

I think admin is alive and that he deliberately stole the coins.

I tried to withdraw millions of DOGE, and I got a funny message when I did:
"You thought the world was your oyster. This time you're not getting your pearl."

To me, this message is the admin admitting that he's run off with my coins.

I just wanted to post a warning about dogecoin mining pools. I have lost an estimated 2 million doge to a fake pool (doge. Cryptopool. It)

I started mining last week and got my first payout. I then left 10MH running over a long weekend. When I got back I had  1 Mill in my account unpaid, but had been expecting at over 2 by calculations from diff and hash rate.

I thought the pool was just lagged out, but when I tried a manual payout I got an interesting message which went a bit like:
"You thought the world was your oyster. This time you're not getting your pearl. "

Basically, it was a sarcastic message from the admin admitting that he had stolen the coins.

(I know there is a dedicated thread about this pool, but I thought the admin's cheeky message would be interesting to some people who still hope that they might get their coins. As a newbie, I can't reply to that thread).