Re: [bitcoin-dev] request BIP number for: "Support for Datastream Compression"

From: Peter Tschipper <peter.tschipper@gmail•com>
To: Bitcoin Dev <bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] request BIP number for: "Support for Datastream Compression"
Date: Tue, 10 Nov 2015 08:46:54 -0800	[thread overview]
Message-ID: <56421F7E.8070305@gmail.com> (raw)
In-Reply-To: <56421F1E.4050302@gmail.com>

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On 10/11/2015 8:45 AM, Peter Tschipper wrote:
> On 10/11/2015 8:30 AM, Tier Nolan via bitcoin-dev wrote:
>>
>>
>> On Tue, Nov 10, 2015 at 4:11 PM, Peter Tschipper
>> <peter.tschipper@gmail•com> wrote:
>>
>>     There are better ways of sending new blocks, that's certainly
>>     true but for sending historical blocks and seding transactions I
>>     don't think so.  This PR is really designed to save bandwidth and
>>     not intended to be a huge performance improvement in terms of
>>     time spent sending.
>>
>>
>> If the main point is for historical data, then sticking to just
>> blocks is the best plan.
>>
> at the beginning yes.
>> Since small blocks don't compress well, you could define a "cblocks"
>> message that handles multiple blocks (just concatenate the block
>> messages as payload before compression). 
>>
> Small block are rare these days (but plenty of historical block), but
> still they get a 10% compression, not bad and I think worthwhile and
> the time it takes to compress small blocks is less that a millisecond
> so no loss there in time.   But still you have a good point and
> something worthy of doing after getting compression to work.  I think
> it's wise to keep it simple at first and build on the success later.
>> The sending peer could combine blocks so that each cblock is
>> compressing at least 10kB of block data (or whatever is optimal).  It
>> is probably worth specifying a maximum size for network buffer
>> reasons (either 1MB or 1 block maximum).
> Good idea. Same answer as above.
>> Similarly, transactions could be combined together and compressed
>> "ctxs".  The inv messages could be modified so that you can request
>> groups of 10-20 transactions.  That would depend on how much of an
>> improvement compressed transactions would represent.
>>
> Good idea. Same answer as above.
>> More generally, you could define a message which is a compressed
>> message holder.  That is probably to complex to be worth the effort
>> though.
> That's actually pretty easy to do and part of the plan.  Sending a
> cmp_block rather than a block makes it all easier to implement.  It's
> just a matter of doing pnode->pushmessage("cmp_block",
> compressed_block); and handling the "cmp_block" command string at the
> other end.
>>
>>  
>>
>>>
>>>     On Tue, Nov 10, 2015 at 5:40 AM, Johnathan Corgan via
>>>     bitcoin-dev <bitcoin-dev@lists•linuxfoundation.org
>>>     <mailto:bitcoin-dev@lists•linuxfoundation.org>> wrote:
>>>
>>>         On Mon, Nov 9, 2015 at 5:58 PM, gladoscc via bitcoin-dev
>>>         <bitcoin-dev@lists•linuxfoundation.org> wrote:
>>>          
>>>
>>>             I think 25% bandwidth savings is certainly considerable,
>>>             especially for people running full nodes in countries
>>>             like Australia where internet bandwidth is lower and
>>>             there are data caps.
>>>
>>>
>>>          This reinforces the idea that such trade-off decisions
>>>         should be be local and negotiated between peers, not a
>>>         required feature of the network P2P.
>>>          
>>>
>>>         -- 
>>>         Johnathan Corgan
>>>         Corgan Labs - SDR Training and Development Services
>>>         http://corganlabs.com
>>>
>>>         _______________________________________________
>>>         bitcoin-dev mailing list
>>>         bitcoin-dev@lists•linuxfoundation.org
>>>         <mailto:bitcoin-dev@lists•linuxfoundation.org>
>>>         https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>>>
>>>
>>>
>>>
>>>     _______________________________________________
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>>
>>
>>
>>
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>


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