foundationdb/fdbserver/StorageMetrics.actor.h

408 lines
15 KiB
C++

/*
* StorageMetrics.actor.h
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Included via StorageMetrics.h
#include "fdbclient/FDBTypes.h"
#include "fdbrpc/simulator.h"
#include "flow/UnitTest.h"
#include "fdbclient/StorageServerInterface.h"
#include "fdbclient/KeyRangeMap.h"
#include "fdbserver/Knobs.h"
#include "flow/actorcompiler.h" // This must be the last #include.
struct StorageMetricSample {
IndexedSet<Key, int64_t> sample;
int64_t metricUnitsPerSample;
StorageMetricSample( int64_t metricUnitsPerSample ) : metricUnitsPerSample(metricUnitsPerSample) {}
int64_t getEstimate( KeyRangeRef keys ) const {
return sample.sumRange( keys.begin, keys.end );
}
KeyRef splitEstimate( KeyRangeRef range, int64_t offset, bool front = true ) const {
auto fwd_split = sample.index( front ? sample.sumTo(sample.lower_bound(range.begin)) + offset : sample.sumTo(sample.lower_bound(range.end)) - offset );
if( fwd_split == sample.end() || *fwd_split >= range.end )
return range.end;
if( !front && *fwd_split <= range.begin )
return range.begin;
auto bck_split = fwd_split;
// Butterfly search - start at midpoint then go in both directions.
while ((fwd_split != sample.end() && *fwd_split < range.end) ||
(bck_split != sample.begin() && *bck_split > range.begin)) {
if (bck_split != sample.begin() && *bck_split > range.begin) {
auto it = bck_split;
bck_split.decrementNonEnd();
KeyRef split = keyBetween(KeyRangeRef(bck_split != sample.begin() ? std::max<KeyRef>(*bck_split,range.begin) : range.begin, *it));
if(!front || (getEstimate(KeyRangeRef(range.begin, split)) > 0 && split.size() <= CLIENT_KNOBS->SPLIT_KEY_SIZE_LIMIT))
return split;
}
if (fwd_split != sample.end() && *fwd_split < range.end) {
auto it = fwd_split;
++it;
KeyRef split = keyBetween(KeyRangeRef(*fwd_split, it != sample.end() ? std::min<KeyRef>(*it, range.end) : range.end));
if(front || (getEstimate(KeyRangeRef(split, range.end)) > 0 && split.size() <= CLIENT_KNOBS->SPLIT_KEY_SIZE_LIMIT))
return split;
fwd_split = it;
}
}
// If we didn't return above, we didn't find anything.
TraceEvent(SevWarn, "CannotSplitLastSampleKey").detail("Range", range).detail("Offset", offset);
return front ? range.end : range.begin;
}
};
TEST_CASE("/fdbserver/StorageMetricSample/simple") {
StorageMetricSample s( 1000 );
s.sample.insert(LiteralStringRef("Apple"), 1000);
s.sample.insert(LiteralStringRef("Banana"), 2000);
s.sample.insert(LiteralStringRef("Cat"), 1000);
s.sample.insert(LiteralStringRef("Cathode"), 1000);
s.sample.insert(LiteralStringRef("Dog"), 1000);
ASSERT(s.getEstimate(KeyRangeRef(LiteralStringRef("A"), LiteralStringRef("D"))) == 5000);
ASSERT(s.getEstimate(KeyRangeRef(LiteralStringRef("A"), LiteralStringRef("E"))) == 6000);
ASSERT(s.getEstimate(KeyRangeRef(LiteralStringRef("B"), LiteralStringRef("C"))) == 2000);
//ASSERT(s.splitEstimate(KeyRangeRef(LiteralStringRef("A"), LiteralStringRef("D")), 3500) == LiteralStringRef("Cat"));
return Void();
}
struct TransientStorageMetricSample : StorageMetricSample {
Deque< std::pair<double, std::pair<Key, int64_t>> > queue;
TransientStorageMetricSample( int64_t metricUnitsPerSample ) : StorageMetricSample(metricUnitsPerSample) {}
bool roll( KeyRef key, int64_t metric ) {
return g_random->random01() < (double)metric / metricUnitsPerSample; //< SOMEDAY: Better randomInt64?
}
// Returns the sampled metric value (possibly 0, possibly increased by the sampling factor)
int64_t addAndExpire( KeyRef key, int64_t metric, double expiration ) {
int64_t x = add( key, metric );
if (x)
queue.push_back( std::make_pair( expiration, std::make_pair( *sample.find(key), -x ) ) );
return x;
}
//FIXME: both versions of erase are broken, because they do not remove items in the queue with will subtract a metric from the value sometime in the future
int64_t erase( KeyRef key ) {
auto it = sample.find(key);
if (it == sample.end()) return 0;
int64_t x = sample.getMetric(it);
sample.erase(it);
return x;
}
void erase( KeyRangeRef keys ) {
sample.erase( keys.begin, keys.end );
}
void poll(KeyRangeMap< vector< PromiseStream< StorageMetrics > > > & waitMap, StorageMetrics m) {
double now = ::now();
while (queue.size() &&
queue.front().first <= now )
{
KeyRef key = queue.front().second.first;
int64_t delta = queue.front().second.second;
ASSERT( delta != 0 );
if( sample.addMetric( key, delta ) == 0 )
sample.erase( key );
StorageMetrics deltaM = m * delta;
auto v = waitMap[key];
for(int i=0; i<v.size(); i++) {
TEST( true ); // TransientStorageMetricSample poll update
v[i].send( deltaM );
}
queue.pop_front();
}
}
void poll() {
double now = ::now();
while (queue.size() &&
queue.front().first <= now )
{
KeyRef key = queue.front().second.first;
int64_t delta = queue.front().second.second;
ASSERT( delta != 0 );
if( sample.addMetric( key, delta ) == 0 )
sample.erase( key );
queue.pop_front();
}
}
private:
int64_t add( KeyRef key, int64_t metric ) {
if (!metric) return 0;
int64_t mag = metric<0 ? -metric : metric;
if (mag < metricUnitsPerSample) {
if ( !roll(key, mag) )
return 0;
metric = metric<0 ? -metricUnitsPerSample : metricUnitsPerSample;
}
if( sample.addMetric( key, metric ) == 0 )
sample.erase( key );
return metric;
}
};
struct StorageServerMetrics {
KeyRangeMap< vector< PromiseStream< StorageMetrics > > > waitMetricsMap;
StorageMetricSample byteSample;
TransientStorageMetricSample iopsSample, bandwidthSample; // FIXME: iops and bandwidth calculations are not effectively tested, since they aren't currently used by data distribution
StorageServerMetrics()
: byteSample( 0 ), iopsSample( SERVER_KNOBS->IOPS_UNITS_PER_SAMPLE ), bandwidthSample( SERVER_KNOBS->BANDWIDTH_UNITS_PER_SAMPLE )
{
}
// Get the current estimated metrics for the given keys
StorageMetrics getMetrics( KeyRangeRef const& keys ) {
StorageMetrics result;
result.bytes = byteSample.getEstimate( keys );
result.bytesPerKSecond = bandwidthSample.getEstimate( keys ) * SERVER_KNOBS->STORAGE_METRICS_AVERAGE_INTERVAL_PER_KSECONDS;
result.iosPerKSecond = iopsSample.getEstimate( keys ) * SERVER_KNOBS->STORAGE_METRICS_AVERAGE_INTERVAL_PER_KSECONDS;
return result;
}
// Called when metrics should change (IO for a given key)
// Notifies waiting WaitMetricsRequests through waitMetricsMap, and updates metricsAverageQueue and metricsSampleMap
void notify( KeyRef key, StorageMetrics& metrics ) {
ASSERT (metrics.bytes == 0); // ShardNotifyMetrics
TEST (metrics.bytesPerKSecond != 0); // ShardNotifyMetrics
TEST (metrics.iosPerKSecond != 0); // ShardNotifyMetrics
double expire = now() + SERVER_KNOBS->STORAGE_METRICS_AVERAGE_INTERVAL;
StorageMetrics notifyMetrics;
if (metrics.bytesPerKSecond)
notifyMetrics.bytesPerKSecond = bandwidthSample.addAndExpire( key, metrics.bytesPerKSecond, expire ) * SERVER_KNOBS->STORAGE_METRICS_AVERAGE_INTERVAL_PER_KSECONDS;
if (metrics.iosPerKSecond)
notifyMetrics.iosPerKSecond = iopsSample.addAndExpire( key, metrics.iosPerKSecond, expire ) * SERVER_KNOBS->STORAGE_METRICS_AVERAGE_INTERVAL_PER_KSECONDS;
if (!notifyMetrics.allZero()) {
auto& v = waitMetricsMap[key];
for(int i=0; i<v.size(); i++) {
TEST( true ); // ShardNotifyMetrics
v[i].send( notifyMetrics );
}
}
}
// Called by StorageServerDisk when the size of a key in byteSample changes, to notify WaitMetricsRequest
// Should not be called for keys past allKeys.end
void notifyBytes( RangeMap<Key, std::vector<PromiseStream<StorageMetrics>>, KeyRangeRef>::Iterator shard, int64_t bytes ) {
ASSERT(shard.end() <= allKeys.end);
StorageMetrics notifyMetrics;
notifyMetrics.bytes = bytes;
for(int i=0; i < shard.value().size(); i++) {
TEST( true ); // notifyBytes
shard.value()[i].send( notifyMetrics );
}
}
// Called by StorageServerDisk when the size of a key in byteSample changes, to notify WaitMetricsRequest
void notifyBytes( KeyRef key, int64_t bytes ) {
if( key >= allKeys.end ) //Do not notify on changes to internal storage server state
return;
notifyBytes(waitMetricsMap.rangeContaining(key), bytes);
}
// Called when a range of keys becomes unassigned (and therefore not readable), to notify waiting WaitMetricsRequests (also other types of wait
// requests in the future?)
void notifyNotReadable( KeyRangeRef keys ) {
auto rs = waitMetricsMap.intersectingRanges(keys);
for (auto r = rs.begin(); r != rs.end(); ++r){
auto &v = r->value();
TEST( v.size() ); // notifyNotReadable() sending errors to intersecting ranges
for (int n=0; n<v.size(); n++)
v[n].sendError( wrong_shard_server() );
}
}
// Called periodically (~1 sec intervals) to remove older IOs from the averages
// Removes old entries from metricsAverageQueue, updates metricsSampleMap accordingly, and notifies
// WaitMetricsRequests through waitMetricsMap.
void poll() {
{ StorageMetrics m; m.bytesPerKSecond = SERVER_KNOBS->STORAGE_METRICS_AVERAGE_INTERVAL_PER_KSECONDS; bandwidthSample.poll(waitMetricsMap, m); }
{ StorageMetrics m; m.iosPerKSecond = SERVER_KNOBS->STORAGE_METRICS_AVERAGE_INTERVAL_PER_KSECONDS; iopsSample.poll(waitMetricsMap, m); }
// bytesSample doesn't need polling because we never call addExpire() on it
}
//static void waitMetrics( StorageServerMetrics* const& self, WaitMetricsRequest const& req );
// This function can run on untrusted user data. We must validate all divisions carefully.
KeyRef getSplitKey( int64_t remaining, int64_t estimated, int64_t limits, int64_t used, int64_t infinity,
bool isLastShard, StorageMetricSample& sample, double divisor, KeyRef const& lastKey, KeyRef const& key, bool hasUsed )
{
ASSERT(remaining >= 0);
ASSERT(limits > 0);
ASSERT(divisor > 0);
if( limits < infinity / 2 ) {
int64_t expectedSize;
if( isLastShard || remaining > estimated ) {
double remaining_divisor = ( double( remaining ) / limits ) + 0.5;
expectedSize = remaining / remaining_divisor;
} else {
// If we are here, then estimated >= remaining >= 0
double estimated_divisor = ( double( estimated ) / limits ) + 0.5;
expectedSize = remaining / estimated_divisor;
}
if( remaining > expectedSize ) {
// This does the conversion from native units to bytes using the divisor.
double offset = (expectedSize - used) / divisor;
if( offset <= 0 )
return hasUsed ? lastKey : key;
return sample.splitEstimate( KeyRangeRef(lastKey, key), offset * ( ( 1.0 - SERVER_KNOBS->SPLIT_JITTER_AMOUNT ) + 2 * g_random->random01() * SERVER_KNOBS->SPLIT_JITTER_AMOUNT ) );
}
}
return key;
}
void splitMetrics( SplitMetricsRequest req ) {
try {
SplitMetricsReply reply;
KeyRef lastKey = req.keys.begin;
StorageMetrics used = req.used;
StorageMetrics estimated = req.estimated;
StorageMetrics remaining = getMetrics( req.keys ) + used;
//TraceEvent("SplitMetrics").detail("Begin", req.keys.begin).detail("End", req.keys.end).detail("Remaining", remaining.bytes).detail("Used", used.bytes);
while( true ) {
if( remaining.bytes < 2*SERVER_KNOBS->MIN_SHARD_BYTES )
break;
KeyRef key = req.keys.end;
bool hasUsed = used.bytes != 0 || used.bytesPerKSecond != 0 || used.iosPerKSecond != 0;
key = getSplitKey( remaining.bytes, estimated.bytes, req.limits.bytes, used.bytes,
req.limits.infinity, req.isLastShard, byteSample, 1, lastKey, key, hasUsed );
if( used.bytes < SERVER_KNOBS->MIN_SHARD_BYTES )
key = std::max( key, byteSample.splitEstimate( KeyRangeRef(lastKey, req.keys.end), SERVER_KNOBS->MIN_SHARD_BYTES - used.bytes ) );
key = getSplitKey( remaining.iosPerKSecond, estimated.iosPerKSecond, req.limits.iosPerKSecond, used.iosPerKSecond,
req.limits.infinity, req.isLastShard, iopsSample, SERVER_KNOBS->STORAGE_METRICS_AVERAGE_INTERVAL_PER_KSECONDS, lastKey, key, hasUsed );
key = getSplitKey( remaining.bytesPerKSecond, estimated.bytesPerKSecond, req.limits.bytesPerKSecond, used.bytesPerKSecond,
req.limits.infinity, req.isLastShard, bandwidthSample, SERVER_KNOBS->STORAGE_METRICS_AVERAGE_INTERVAL_PER_KSECONDS, lastKey, key, hasUsed );
ASSERT( key != lastKey || hasUsed);
if( key == req.keys.end )
break;
reply.splits.push_back_deep( reply.splits.arena(), key );
StorageMetrics diff = (getMetrics( KeyRangeRef(lastKey, key) ) + used);
remaining -= diff;
estimated -= diff;
used = StorageMetrics();
lastKey = key;
}
reply.used = getMetrics( KeyRangeRef(lastKey, req.keys.end) ) + used;
req.reply.send(reply);
} catch (Error& e) {
req.reply.sendError(e);
}
}
void getPhysicalMetrics( GetPhysicalMetricsRequest req, StorageBytes sb ){
GetPhysicalMetricsReply rep;
// SOMEDAY: make bytes dynamic with hard disk space
rep.load = getMetrics(allKeys);
if (sb.free < 1e9 && g_random->random01() < 0.1)
TraceEvent(SevWarn, "PhysicalDiskMetrics")
.detail("Free", sb.free)
.detail("Total", sb.total)
.detail("Available", sb.available)
.detail("Load", rep.load.bytes);
rep.free.bytes = sb.free;
rep.free.iosPerKSecond = 10e6;
rep.free.bytesPerKSecond = 100e9;
rep.capacity.bytes = sb.total;
rep.capacity.iosPerKSecond = 10e6;
rep.capacity.bytesPerKSecond = 100e9;
req.reply.send(rep);
}
Future<Void> waitMetrics(WaitMetricsRequest req, Future<Void> delay);
private:
static void collapse( KeyRangeMap<int>& map, KeyRef const& key ) {
auto range = map.rangeContaining(key);
if (range == map.ranges().begin() || range == map.ranges().end()) return;
int value = range->value();
auto prev = range; --prev;
if (prev->value() != value) return;
KeyRange keys = KeyRangeRef( prev->begin(), range->end() );
map.insert( keys, value );
}
static void add( KeyRangeMap<int>& map, KeyRangeRef const& keys, int delta ) {
auto rs = map.modify(keys);
for(auto r = rs.begin(); r != rs.end(); ++r)
r->value() += delta;
collapse( map, keys.begin );
collapse( map, keys.end );
}
};
//Contains information about whether or not a key-value pair should be included in a byte sample
//Also contains size information about the byte sample
struct ByteSampleInfo {
bool inSample;
//Actual size of the key value pair
int64_t size;
//The recorded size of the sample (max of bytesPerSample, size)
int64_t sampledSize;
};
//Determines whether a key-value pair should be included in a byte sample
//Also returns size information about the sample
ByteSampleInfo isKeyValueInSample(KeyValueRef keyValue);
#include "flow/unactorcompiler.h"