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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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33
controller/SqliteNetworkController.cpp
View file

@ -296,6 +296,12 @@ SqliteNetworkController::~SqliteNetworkController()
NetworkController::ResultCode SqliteNetworkController::doNetworkConfigRequest(const InetAddress &fromAddr,const Identity &signingId,const Identity &identity,uint64_t nwid,const Dictionary &metaData,uint64_t haveRevision,Dictionary &netconf)
{
// Decode some stuff from metaData
const unsigned int clientMajorVersion = (unsigned int)metaData.getHexUInt(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_NODE_MAJOR_VERSION,0);
const unsigned int clientMinorVersion = (unsigned int)metaData.getHexUInt(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_NODE_MINOR_VERSION,0);
const unsigned int clientRevision = (unsigned int)metaData.getHexUInt(ZT_NETWORKCONFIG_REQUEST_METADATA_KEY_NODE_REVISION,0);
const bool clientIs104 = (Utils::compareVersion(clientMajorVersion,clientMinorVersion,clientRevision,1,0,4) >= 0);
Mutex::Lock _l(_lock);
// Note: we can't reuse prepared statements that return const char * pointers without
@ -418,13 +424,6 @@ NetworkController::ResultCode SqliteNetworkController::doNetworkConfigRequest(co
if (!member.authorized)
return NetworkController::NETCONF_QUERY_ACCESS_DENIED;
// If netconf is unchanged from client reported revision, just tell client they're up to date
// Temporarily disabled -- old version didn't do this, and we'll go ahead and
// test more thoroughly before enabling this optimization.
//if ((haveRevision > 0)&&(haveRevision == network.revision))
// return NetworkController::NETCONF_QUERY_OK_BUT_NOT_NEWER;
// Create and sign netconf
netconf.clear();
@ -581,7 +580,8 @@ NetworkController::ResultCode SqliteNetworkController::doNetworkConfigRequest(co
if ((ipNetmaskBits <= 0)||(ipNetmaskBits > 32))
continue;
switch((IpAssignmentType)sqlite3_column_int(_sGetIpAssignmentsForNode,0)) {
const IpAssignmentType ipt = (IpAssignmentType)sqlite3_column_int(_sGetIpAssignmentsForNode,0);
switch(ipt) {
case ZT_IP_ASSIGNMENT_TYPE_ADDRESS:
haveStaticIpAssignment = true;
break;
@ -592,13 +592,15 @@ NetworkController::ResultCode SqliteNetworkController::doNetworkConfigRequest(co
continue;
}
// We send both routes and IP assignments -- client knows which is
// which by whether address ends in all zeroes after netmask.
char tmp[32];
Utils::snprintf(tmp,sizeof(tmp),"%d.%d.%d.%d/%d",(int)ip[12],(int)ip[13],(int)ip[14],(int)ip[15],ipNetmaskBits);
if (v4s.length())
v4s.push_back(',');
v4s.append(tmp);
// 1.0.4 or newer clients support network routes in addition to IPs.
// Older clients only support IP address / netmask entries.
if ((clientIs104)||(ipt == ZT_IP_ASSIGNMENT_TYPE_ADDRESS)) {
char tmp[32];
Utils::snprintf(tmp,sizeof(tmp),"%d.%d.%d.%d/%d",(int)ip[12],(int)ip[13],(int)ip[14],(int)ip[15],ipNetmaskBits);
if (v4s.length())
v4s.push_back(',');
v4s.append(tmp);
}
}
if (!haveStaticIpAssignment) {
@ -1388,7 +1390,6 @@ unsigned int SqliteNetworkController::_doCPGet(
const char *result = "";
switch(this->doNetworkConfigRequest(InetAddress(),sigid,memid,nwid,Dictionary(),hr,netconf)) {
case NetworkController::NETCONF_QUERY_OK: result = "OK"; break;
case NetworkController::NETCONF_QUERY_OK_BUT_NOT_NEWER: result = "OK_BUT_NOT_NEWER"; break;
case NetworkController::NETCONF_QUERY_OBJECT_NOT_FOUND: result = "OBJECT_NOT_FOUND"; break;
case NetworkController::NETCONF_QUERY_ACCESS_DENIED: result = "ACCESS_DENIED"; break;
case NetworkController::NETCONF_QUERY_INTERNAL_SERVER_ERROR: result = "INTERNAL_SERVER_ERROR"; break;