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Viewing changes to xr/DispatchAlgorithms/storedip/target.cc

  • Committer: Bazaar Package Importer
  • Author(s): Stefan Ritter
  • Date: 2010-07-05 16:27:00 UTC
  • Revision ID: james.westby@ubuntu.com-20100705162700-0g08tfav8ee9y51u
Tags: upstream-2.65
Import upstream version 2.65

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xr/DispatchAlgorithms/storedip/target.cc
 
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#include "storedip"
 
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unsigned StoredIp::target(struct in_addr clientip,
 
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                          BackendVector const &targetlist) {
 
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    PROFILE("StoredIP::target");
 
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    IPStore::on();
 
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    msg(Mstr("Starting stored-ip dispatcher\n"));
 
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    int tb;
 
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    if ( (tb = IPStore::target(clientip)) >= 0 ) {
 
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        unsigned target = tb;
 
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        IPStore::clear(clientip);
 
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        if (balancer.backend(target).available()) {
 
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            // Historical target is up, go there!
 
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            msg(Mstr("Sending ") + Mstr(inet_ntoa(clientip)) + " to " +
 
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                balancer.backend(target).description() + "\n");
 
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            return target;
 
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        }
 
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        msg (Mstr("Historical target ") +
 
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             balancer.backend(target).description() + " unavailable\n"); 
 
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        if (config.dispatchmode() == Dispatchmode::m_strict_stored_ip)
 
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            throw Error("Stored-IP algorithm: target back end " +
 
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                        balancer.backend(target).description() +
 
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                        " unavailable");
 
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    }
 
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    // Client is seen for the first time, or after the timout period, or
 
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    // their preferred back end is down (and we're in lax mode ofc).
 
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    // Treat as new connection.
 
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    Leastconn l;
 
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    if (!config.removereservations())
 
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        return l.target(clientip, targetlist);
 
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    else {
 
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        BackendVector tlist = targetlist;
 
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        while (true) {
 
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            try {
 
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                return l.target(clientip, tlist);
 
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            } catch (...) {
 
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                // We're out of back ends and need to clear up the IP store to retry.
 
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                // We give it a sec, remove the oldest entry, and rebuild the
 
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                // target list for the least-connections dispatch algorithm.
 
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                warnmsg("Out of back ends, releasing oldest client entry and retrying\n");
 
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                IPStore::clearoldest();
 
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                sleep(1);
 
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                BackendVector newlist;
 
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                for (unsigned int i = 0; i < balancer.nbackends(); i++)
 
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                    if (balancer.backend(i).available())
 
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                        newlist.add(i);
 
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                tlist = newlist;
 
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            }
 
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        }
 
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    }
 
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}
 
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