Dear Epic Cash Community,
We are bringing the network back online! Link below includes the necessary technical steps to get you reconnected to the Epic Cash blockchain. Please follow the instructions carefully and do not improvise:# Summary
This release rolls back the chain to the last good state (height 861141).
This requires you to synchronize your wallet. In order to do this, perform the following additional step.
- The package contains an additional executable: `epic-wallet-tool`;
- **After** you have the new server version running normally;
- (windows only) Place the `epic-wallet-tool` executable in the same directory as your wallet executable;
- Execute the `epic-wallet-tool`.
Detailed instructions can be found in:
https://drive.google.com/file/d/1Ucx7LZd7gkfmlABpgh2VDjlxH6nwSXLH/view?usp=sharing# Epic Server 2.15 Release Notes
With this release, we address the issue of corrupt blocks that were found a couple weeks ago.
We do this by rolling back the chain the last good state (height 861141).
Because of the periodic compaction, we cannot roll back to this height directly.
Instead, we replace the existing chain data by a "canonical" one.
Instructions and details below.
## What's new?
- Automated chain data rollback using canonical chain data
- Check for bad headers and ban peers who send them
- Avoid loading subsequent chunks if headers_received returns false
- Update build instructions for macOS
- Fix graph weight for cuckoo cycles
- Change version checker domain name
## Update instructions
Please follow the instructions below when installing this new version.
Contact support if something seems wrong.
### Server
1. Download the 2.15.0 package
- Windows:
https://d1ftoepmu0es39.cloudfront.net/epic-server-2.15.0.zip - Debian (Linux):
https://d1ftoepmu0es39.cloudfront.net/epic_2.15.0-1_amd64.zip2. Extract the zip file you downloaded
- For Windows, you'll get the following files:
- `epic.exe` (this is the usual epic server executable)
- `foundation.json` (this is the usual `foundation.json` file)
- `epic-wallet-tool.exe` (this is a tool specific for this release)
- For Debian (Linux), you'll get the following files:
- `epic_2.15.0-1_amd64.deb` (this is the usual package)
- `epic-wallet-tool` (this is a tool specific for this release)
3. Install and run the server as usual
- On Windows, just execute `epic.exe`
- On Debian (Linux):
- Install with: `dpkg -i epic_2.15.0-1_amd64.deb`
- Then run: `epic`
You will see some messages detailing what is happening. In summary:
1. the "canonical" chain data will be donwloaded (please wait, it may take a while)
2. your pre-existing chain data will be backed up
3. and then replaced by the "canonical" one
4. That's it; the server should be running normally now
### Wallet
Because of the rollback, you'll need to update your wallet.
This will restore your balance to what it was at height 861141.
1. **(Windows only)** Place the `epic-wallet-tool.exe` file in the same directory as the `epic-wallet.exe` one that you already have.
2. Execute the `epic-wallet-tool` program
You will see some messages detailing what is happening. In summary:
1. You'll be asked to provide the path to your wallet data
- Use the listed candidate path if you have not customized your wallet path
2. Your wallet data will be backed up
3. Your wallet will be restored from the seed, using the "canonical" chain data
3. That's it; you can run `epic-wallet info` to check your new balance
Alternatively, you can simply run `epic-wallet check` yourself.
## Details
### Bad commits
These are the output commits we identified as corrupt.
https://explorer.epic.tech/blockdetail/083bb9b34247dc5f02539ddf26d1c59228523e1702775754f7b6e39154ced9a4d4https://explorer.epic.tech/blockdetail/09e73642a40c87cfdb3ab064e748db6d8bf40a94bf52b7e22838ff29f1ba9406e2### Automatic Compaction
This is a feature implemented in Epic that makes use of the "cut-through" capability of MimbleWimble to preserve storage and decrease chain size.
This means that data older than some period and not needed anymore is erased.
Unfortunately, it also limits how far to the past the chain can rollback if something bad happens.
# FAQ
## Can I keep using my own chain data instead of have it replaced by the `canonical` one?
Yes, but it would require manual steps:
1. Stop the server
2. Restore the `chain_data` backup
3. Start the server again
Alternatively, before running the new version:
1. Create a file named `2-15-rollback-flag` in the parent directory of your `chain_data`
## Can I sync from zero?
Yes, but it would require manual steps:
Before running the new version:
1. Create a file named `2-15-rollback-flag` in the parent directory of your `chain_data`
2. Delete your `chain_data`
## What will happen with people who keep using an old version?
The version checker will stop them from running.
If they somehow avoid the version checker, and they have a tainted `chain_data`, they will get rejected and banned.
## What will happen to people who keep using the old `chain_data`?
They will continue on their fork of the chain.
They won't sync with the rolled-back chain and if they try they will get banned.
## Can I keep the transaction history of my wallet?
Maybe. I don't know precisely how the wallet database works.
Here is what you can try:
Don't execute the `epic-wallet-tool`. Instead, just run:
```
epic-wallet check
```
It might not work if you have transactions more recent than height 861141.
In this case, you should follow the normal procedure and wait until the height is high enough so you can try again.
## Why version 2.15? Where is version 2.14
Version 2.14 was used for internal beta testing.
Releasing as version 2.15 allows us to use the version checker to make sure there are no beta versions running.
A lot of hard work has been done by our talented devs and tech volunteers – coding, debugging, testing documenting, and a lot more. Huge thanks and mad respect (in no particular order) to Filipe, Blacktyger, Poolboy, JLong, James Freeman, Robert, Yoga, and Yuri. Special thanks go out to David Burkett for initially notifying us about the bug, and providing technical guidance to resolve it.
Once your new server is synched up and wallet checked, you may resume mining. There will be additional announcements as we progress.
Thank you for your patience, support and understanding!
