Parity Logs – Locating Parity Log Files in Daemon Mode

Send Stderr And Stdout To A Log File

If you want to overwrite the log file each time you start your command:

parity [options] > /tmp/parity.log 2>&1

If you want to append to your log file each time you start your command:

parity [options] >> /tmp/parity.log 2>&1

Send Stderr And Stdout To Separate Log Files While Viewing Output

And if you want to log stderr and stdout into separate log files while viewing the output on your console:

parity [options] > >(tee stdout.log) 2> >(tee stderr.log >&2)

Reference How do I write stderr to a file while using “tee” with a pipe?.

If you want to create a script file to run this command, you will have to use #!/bin/bash (instead of #!/bin/sh) in the first line of the file as this redirection is bash specific:

#!/bin/bash

cd $HOME/Parity

parity [options] > >(tee stdout.log) 2> >(tee stderr.log >&2)

Save the above into $HOME/bin/runParity, chmod 700 $HOME/bin/runParity and your can then type runParity (or $HOME/bin/runParity) to start it.

geth and parity have differents methods to save the ethereum blockchain in their internal format. I made many benchs because i find it so long just to use a Wallet.

The pruning mode is how the block data are saved. With the archive mode, all states are saved. So, you know the state at each moment without to reload all the blockchain. With fast and light, we assume that we don't need all this information but only the current state and few before, so we remove many intermediates states.

On geth, the --fast method saves a state of the blockchain at block B[-1500] and all the states after this block (B[-1] is the last block, B[-2] is the before last block ...). So it is possible to rewind at the state of 1500 last blocks. With a full blockchain, you can do it for all blocks.

In parity, there are 4 pruning modes or journalDB algorithms:

• Archive (Archive): as geth Archive we keep all states
• Fast (OverlayRecent): as geth Fast we keep all the full states of the B[-i] blocks
• Light (EarlyMerge): we keep all the states of the B[-i] blocks but in differential (so it is smaller than fast but slower access)
• Basic (RefCounted): we keep all the states of the B[-i] blocks like with OverlayRecent but we remove states after x changes... so we have only the xth last changes

Benchmarks done on i7 3720QM 16GB ram with Geth 1.4.4 (Homestead with 1.6Mi blocks)

_____________________________________________
| Option | Disk Used | Time | Disk Written  |
|--------|-----------|------|---------------|
| none   | 19.GB     | 5h00 | 1TB           |
| fast   | 3.7GB     | 1h00 | 100GB         |
---------------------------------------------

Benchmarks done on i7 3720QM 16GB ram with Geth 1.5.0 unstable (Homestead with 1.6Mi blocks found at https://gitter.im/ethereum/go-ethereum?at=574d26c010f0fed86f49b32f)

__________________________________________________
| command     | Disk Used | Time | Disk Written  |
|-------------|-----------|------|---------------|
| geth        | 21GB      | 5h00 | 150GB         |
| geth --fast | 4.2GB     | 21m  | 35GB          |
| geth export | 1.5GB     | 10m  |               |
| geth import | 21GB      | 3h30 |               |
--------------------------------------------------

Benchmarks done on i7 3720QM 16GB ram with Parity 1.2 (Homestead with 1.6Mi blocks)

_____________________________________________
| Option | Disk Used | Time | Disk Written  |
|--------|-----------|------|---------------|
| archive| 19.GB     | 2h00 | 300GB         |
| fast   | 3.7GB     | 1h30 | 20GB          |
| light  | 2.5GB     | 2h00 | 130GB         |
---------------------------------------------

Note: When you have a node with a blockchain, you can dump the chaindata of geth directory to use it with your other computers. I check it with Linux, Windows and OS X.

Note: if you use --cache with 1024, it could be faster. But it is not significant on my system. The same goes for the --jitvm

Note: the ethereum blockchain saved the final state after transactions but it is safer to replay the transactions to check them.