Method updateSlave

src/master/allocator/mesos/hierarchical.cpp:1112–1174

void HierarchicalAllocatorProcess::updateSlave(
    const SlaveID& slaveId,
    const SlaveInfo& info,
    const Option<Resources>& total,
    const Option<vector<SlaveInfo::Capability>>& capabilities)
{
  CHECK(initialized);
  CHECK_EQ(slaveId, info.id());

  Slave& slave = *CHECK_NOTNONE(getSlave(slaveId));

  bool updated = false;

  // Remove all offer filters for this slave if it was restarted with changed
  // attributes. We do this because schedulers might have decided that they're
  // not interested in offers from this slave based on the non-presence of some
  // required attributes, and right now they have no other way of learning
  // about this change.
  // TODO(bennoe): Once the agent lifecycle design is implemented, there is a
  // better way to notify frameworks about such changes and let them make this
  // decision. We should think about ways to safely remove this check at that
  // point in time.
  if (!(Attributes(info.attributes()) == Attributes(slave.info.attributes()))) {
    updated = true;
    removeFilters(slaveId);
  }

  if (!(slave.info == info)) {
    updated = true;

    // We unconditionally overwrite the old domain and hostname: Even though
    // the master places some restrictions on this (i.e. agents are not allowed
    // to reregister with a different hostname) inside the allocator it
    // doesn't matter, as the algorithm will work correctly either way.
    slave.info = info;
  }

  // Update agent capabilities.
  if (capabilities.isSome()) {
    protobuf::slave::Capabilities newCapabilities(capabilities.get());
    protobuf::slave::Capabilities oldCapabilities(slave.capabilities);

    slave.capabilities = newCapabilities;

    if (newCapabilities != oldCapabilities) {
      updated = true;

      LOG(INFO) << "Agent " << slaveId << " (" << slave.info.hostname() << ")"
                << " updated with capabilities " << slave.capabilities;
    }
  }

  if (total.isSome()) {
    updated = updateSlaveTotal(slaveId, total.get()) || updated;

    LOG(INFO) << "Agent " << slaveId << " (" << slave.info.hostname() << ")"
              << " updated with total resources " << total.get();
  }