Future<http::Response> Master::QuotaHandler::_set(
const QuotaInfo& quotaInfo,
bool forced) const
{
if (forced) {
VLOG(1) << "Using force flag to override quota capacity heuristic check";
} else {
// Validate whether a quota request can be satisfied.
Option<Error> error = capacityHeuristic(quotaInfo);
if (error.isSome()) {
return Conflict(
"Heuristic capacity check for set quota request failed: " +
error.get().message);
}
}
Quota quota = Quota{quotaInfo};
// Populate master's quota-related local state. We do this before updating
// the registry in order to make sure that we are not already trying to
// satisfy a request for this role (since this is a multi-phase event).
// NOTE: We do not need to remove quota for the role if the registry update
// fails because in this case the master fails as well.
master->quotas[quotaInfo.role()] = quota;
// Update the registry with the new quota and acknowledge the request.
return master->registrar->apply(Owned<Operation>(
new quota::UpdateQuota(quotaInfo)))
.then(defer(master->self(), [=](bool result) -> Future<http::Response> {
// See the top comment in "master/quota.hpp" for why this check is here.
CHECK(result);
master->allocator->setQuota(quotaInfo.role(), quota);
// Rescind outstanding offers to facilitate satisfying the quota request.
// NOTE: We set quota before we rescind to avoid a race. If we were to
// rescind first, then recovered resources may get allocated again
// before our call to `setQuota` was handled.
// The consequence of setting quota first is that (in the hierarchical
// allocator) it will trigger an allocation. This means the rescinded
// offer resources will only be available to quota once another
// allocation is invoked.
// This can be resolved in the future with an explicit allocation call,
// and this solution is preferred to having the race described earlier.
rescindOffers(quotaInfo);
return OK();
}));
}
Future<http::Response> Master::QuotaHandler::set(
const http::Request& request) const
{
VLOG(1) << "Setting quota from request: '" << request.body << "'";
// Authenticate and authorize the request.
// TODO(alexr): Check Master::Http::authenticate() for an example.
// Check that the request type is POST which is guaranteed by the master.
CHECK_EQ("POST", request.method);
// Validate request and extract JSON.
Try<hashmap<string, string>> decode = http::query::decode(request.body);
if (decode.isError()) {
return BadRequest("Failed to decode set quota request query string ('" +
request.body + "'): " +
decode.error());
}
hashmap<string, string> values = decode.get();
if (!values.contains("resources")) {
return BadRequest("Failed to parse set quota request query string ('" +
request.body + "'): Missing 'resources'");
}
Try<google::protobuf::RepeatedPtrField<Resource>> resources =
parseResources(values["resources"]);
if (resources.isError()) {
return BadRequest("Failed to parse set quota request query string ('" +
request.body + "'): " + resources.error());
}
// Create the `QuotaInfo` protobuf message from the request JSON.
Try<QuotaInfo> create = createQuotaInfo(resources.get());
if (create.isError()) {
return BadRequest("Failed to create QuotaInfo from set quota request "
"query string '(" + request.body + "'): " +
create.error());
}
// Check that the `QuotaInfo` is a valid quota request.
Try<Nothing> validate = quota::validation::quotaInfo(create.get());
if (validate.isError()) {
return BadRequest("Failed to validate set quota request query string: ('" +
request.body + "'): " + validate.error());
}
// Check that the role is known by the master.
// TODO(alexr): Once we are able to dynamically add roles, we should stop
// checking whether the requested role is known to the master, because an
// operator may set quota for a role that is about to be introduced.
if (!master->roles.contains(create.get().role())) {
return BadRequest("Failed to validate set quota request query string: ('" +
request.body +"')': Unknown role: '" +
create.get().role() + "'");
}
// Check that we are not updating an existing quota.
// TODO(joerg84): Update error message once quota update is in place.
if (master->quotas.contains(create.get().role())) {
return BadRequest("Failed to validate set quota request query string: ('" +
request.body + "')': "
"Can not set quota for a role that already has quota");
}
const QuotaInfo& quotaInfo = create.get();
// Validate whether a quota request can be satisfied.
Option<Error> error = capacityHeuristic(quotaInfo);
if (error.isSome()) {
return Conflict("Heuristic capacity check for set quota request failed: " +
error.get().message);
}
// Populate master's quota-related local state. We do this before updating
// the registry in order to make sure that we are not already trying to
// satisfy a request for this role (since this is a multi-phase event).
// NOTE: We do not need to remove quota for the role if the registry update
// fails because in this case the master fails as well.
master->quotas[quotaInfo.role()] = Quota{quotaInfo};
// Update the registry with the new quota and acknowledge the request.
return master->registrar->apply(Owned<Operation>(
new quota::UpdateQuota(quotaInfo)))
.then(defer(master->self(), [=](bool result) -> Future<http::Response> {
// See the top comment in "master/quota.hpp" for why this check is here.
CHECK(result);
master->allocator->setQuota(quotaInfo.role(), quotaInfo);
return OK();
}));
}