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Eliminate some poorly thought out optimizations from the netconf/controller interaction,

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and go ahead and bump version to 1.0.4.

For a while in 1.0.3 -dev I was trying to optimize out repeated network controller
requests by using a ratcheting mechanism. If the client received a network config
that was indeed different from the one it had, it would respond by instantlly
requesting it again.

Not sure what I was thinking. It's fundamentally unsafe to respond to a message
with another message of the same type -- it risks a race condition. In this case
that's exactly what could happen.

It just isn't worth the added complexity to avoid a tiny, tiny amount of network
overhead, so I've taken this whole path out.

A few extra bytes every two minutes isn't worth fretting about, but as I recall
the reason for this optimization was to save CPU on the controller. This can be
achieved by just caching responses in memory *there* and serving those same
responses back out if they haven't changed.

I think I developed that 'ratcheting' stuff before I went full time on this. It's
hard to develop stuff like this without hours of sustained focus.
This commit is contained in:
Adam Ierymenko 2015-07-23 09:50:10 -07:00
parent e2a2993b18
commit 3ba54c7e35
7 changed files with 55 additions and 80 deletions
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13
node/Network.cpp
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@ -38,6 +38,8 @@
#include "Buffer.hpp"
#include "NetworkController.hpp"
#include "../version.h"
namespace ZeroTier {
const ZeroTier::MulticastGroup Network::BROADCAST(ZeroTier::MAC(0xffffffffffffULL),0);
@ -255,9 +257,18 @@ void Network::requestConfiguration()
}
TRACE("requesting netconf for network %.16llx from controller %s",(unsigned long long)_id,controller().toString().c_str());
// TODO: in the future we will include things like join tokens here, etc.
Dictionary metaData;
metaData.setHex(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_NODE_MAJOR_VERSION,ZEROTIER_ONE_VERSION_MAJOR);
metaData.setHex(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_NODE_MINOR_VERSION,ZEROTIER_ONE_VERSION_MINOR);
metaData.setHex(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_NODE_REVISION,ZEROTIER_ONE_VERSION_REVISION);
std::string mds(metaData.toString());
Packet outp(controller(),RR->identity.address(),Packet::VERB_NETWORK_CONFIG_REQUEST);
outp.append((uint64_t)_id);
outp.append((uint16_t)0); // no meta-data
outp.append((uint16_t)mds.length());
outp.append((const void *)mds.data(),(unsigned int)mds.length());
{
Mutex::Lock _l(_lock);
if (_config)