1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
/**
* Copyright (C) 2022-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include "mongo/base/status.h"
#include "mongo/bson/bsonobj.h"
#include "mongo/db/concurrency/d_concurrency.h"
#include "mongo/db/curop.h"
#include "mongo/db/namespace_string.h"
#include "mongo/db/query/partitioned_cache.h"
#include "mongo/db/query/plan_explainer.h"
#include "mongo/db/query/request_shapifier.h"
#include "mongo/db/query/util/memory_util.h"
#include "mongo/db/service_context.h"
#include <cstdint>
#include <memory>
namespace mongo {
class OpDebug;
class AggregateCommandRequest;
class FindCommandRequest;
namespace {
/**
* Type we use to render values to BSON.
*/
using BSONNumeric = long long;
} // namespace
namespace telemetry {
/**
* An aggregated metric stores a compressed view of data. It balances the loss of information
* with the reduction in required storage.
*/
struct AggregatedMetric {
/**
* Aggregate an observed value into the metric.
*/
void aggregate(uint64_t val) {
sum += val;
max = std::max(val, max);
min = std::min(val, min);
sumOfSquares += val * val;
}
void appendTo(BSONObjBuilder& builder, const StringData& fieldName) const {
BSONObjBuilder metricsBuilder = builder.subobjStart(fieldName);
metricsBuilder.append("sum", (BSONNumeric)sum);
metricsBuilder.append("max", (BSONNumeric)max);
metricsBuilder.append("min", (BSONNumeric)min);
metricsBuilder.append("sumOfSquares", (BSONNumeric)sumOfSquares);
metricsBuilder.done();
}
uint64_t sum = 0;
// Default to the _signed_ maximum (which fits in unsigned range) because we cast to
// BSONNumeric when serializing.
uint64_t min = (uint64_t)std::numeric_limits<int64_t>::max;
uint64_t max = 0;
/**
* The sum of squares along with (an externally stored) count will allow us to compute the
* variance/stddev.
*/
uint64_t sumOfSquares = 0;
};
extern CounterMetric telemetryStoreSizeEstimateBytesMetric;
// Used to aggregate the metrics for one telemetry key over all its executions.
class TelemetryEntry {
public:
TelemetryEntry(std::unique_ptr<RequestShapifier> requestShapifier,
NamespaceStringOrUUID nss,
const BSONObj& cmdObj)
: firstSeenTimestamp(Date_t::now().toMillisSinceEpoch() / 1000, 0),
requestShapifier(std::move(requestShapifier)),
nss(nss),
oldTelemetryKey(cmdObj.copy()) {
telemetryStoreSizeEstimateBytesMetric.increment(sizeof(TelemetryEntry) + sizeof(BSONObj));
}
~TelemetryEntry() {
telemetryStoreSizeEstimateBytesMetric.decrement(sizeof(TelemetryEntry) + sizeof(BSONObj));
}
BSONObj toBSON() const {
BSONObjBuilder builder{sizeof(TelemetryEntry) + 100};
builder.append("lastExecutionMicros", (BSONNumeric)lastExecutionMicros);
builder.append("execCount", (BSONNumeric)execCount);
queryExecMicros.appendTo(builder, "queryExecMicros");
docsReturned.appendTo(builder, "docsReturned");
builder.append("firstSeenTimestamp", firstSeenTimestamp);
return builder.obj();
}
/**
* Redact a given telemetry key and set _keySize.
*/
BSONObj computeTelemetryKey(OperationContext* opCtx,
bool applyHmacToIdentifiers,
std::string hmacKey) const;
/**
* Timestamp for when this query shape was added to the store. Set on construction.
*/
const Timestamp firstSeenTimestamp;
/**
* Last execution time in microseconds.
*/
uint64_t lastExecutionMicros = 0;
/**
* Number of query executions.
*/
uint64_t execCount = 0;
AggregatedMetric queryExecMicros;
AggregatedMetric docsReturned;
std::unique_ptr<RequestShapifier> requestShapifier;
NamespaceStringOrUUID nss;
// TODO: SERVER-73152 remove oldTelemetryKey when RequestShapifier is used for agg.
BSONObj oldTelemetryKey;
};
struct TelemetryPartitioner {
// The partitioning function for use with the 'Partitioned' utility.
std::size_t operator()(const std::size_t k, const std::size_t nPartitions) const {
return k % nPartitions;
}
};
struct TelemetryStoreEntryBudgetor {
size_t operator()(const std::size_t key, const std::shared_ptr<TelemetryEntry>& value) {
// The buget estimator for <key,value> pair in LRU cache accounts for the size of the key
// and the size of the metrics, including the bson object used for generating the telemetry
// key at read time.
return sizeof(TelemetryEntry) + sizeof(std::size_t) + value->oldTelemetryKey.objsize();
}
};
using TelemetryStore = PartitionedCache<std::size_t,
std::shared_ptr<TelemetryEntry>,
TelemetryStoreEntryBudgetor,
TelemetryPartitioner>;
/**
* Acquire a reference to the global telemetry store.
*/
TelemetryStore& getTelemetryStore(OperationContext* opCtx);
/**
* Register a request for telemetry collection. The telemetry machinery may decide not to
* collect anything but this should be called for all requests. The decision is made based on
* the feature flag and telemetry parameters such as rate limiting.
*
* The caller is still responsible for subsequently calling writeTelemetry() once the request is
* completed.
*
* Note that calling this affects internal state. It should be called once for each request for
* which telemetry may be collected.
* TODO SERVER-73152 remove request-specific registers, leave only registerRequest
*/
void registerAggRequest(const AggregateCommandRequest& request, OperationContext* opCtx);
void registerRequest(std::unique_ptr<RequestShapifier> requestShapifier,
const NamespaceString& collection,
OperationContext* opCtx,
const boost::intrusive_ptr<ExpressionContext>& expCtx);
/**
* Writes telemetry to the telemetry store for the operation identified by `telemetryKey`.
*/
void writeTelemetry(OperationContext* opCtx,
boost::optional<size_t> telemetryKeyHash,
boost::optional<BSONObj> telemetryKey,
std::unique_ptr<RequestShapifier> requestShapifier,
uint64_t queryExecMicros,
uint64_t docsReturned);
/**
* Serialize the FindCommandRequest according to the Options passed in. Returns the serialized BSON
* with hmac applied to all field names and literals.
*/
BSONObj makeTelemetryKey(const FindCommandRequest& findCommand,
const SerializationOptions& opts,
const boost::intrusive_ptr<ExpressionContext>& expCtx,
boost::optional<const TelemetryEntry&> existingMetrics = boost::none);
} // namespace telemetry
} // namespace mongo
|
