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# 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.
#
global:
cpp_namespace: "mongo::analyze_shard_key"
cpp_includes:
- "mongo/client/read_preference.h"
- "mongo/s/analyze_shard_key_util.h"
imports:
- "mongo/client/read_preference_setting.idl"
- "mongo/db/basic_types.idl"
- "mongo/db/keypattern.idl"
enums:
MonotonicityType:
description: "The monotonicity type of a shard key."
type: string
values:
kMonotonic: "monotonic"
kNotMonotonic: "not monotonic"
kUnknown: "unknown"
structs:
ValueFrequencyMetrics:
description: "The value and frequency of a shard key value."
strict: false
fields:
value:
type: object_owned
frequency:
type: long
validator: { gt: 0 }
MonotonicityMetrics:
description: "The metrics about the monotonicity of a shard key, i.e. whether its value is
monotonically changing in insertion order."
strict: false
fields:
recordIdCorrelationCoefficient:
type: double
description: "The RecordId correlation coefficient calculated by the monotonicity check.
This is only set if the monotonicity check occurred, i.e. if the shard key
has a supporting index and the collection is not clustered."
validator:
gte: -1
lte: 1
optional: true
type:
type: MonotonicityType
description: "The monotonicity type."
KeyCharacteristicsMetrics:
description: "The metrics about the characteristics of a shard key."
strict: false
fields:
numDocs:
type: long
description: "The number of the documents in the collection."
validator: { gte: 0 }
optional: true
isUnique:
type: bool
description: "Whether the shard key index enforces a uniqueness constraint."
optional: true
numDistinctValues:
type: long
description: "The number of distinct shard key values in the collection."
validator: { gte: 0 }
optional: true
mostCommonValues:
type: array<ValueFrequencyMetrics>
description: "The value and frequency of the most common shard key values."
optional: true
monotonicity:
type: MonotonicityMetrics
description: "The monotonicity metrics for the shard key."
optional: true
avgDocSizeBytes:
type: long
description: "The average document size in bytes."
validator: { gte: 0 }
optional: true
numOrphanDocs:
type: long
description: "The number of the orphan documents in the collection."
validator: { gte: 0 }
optional: true
ReadSampleSize:
description: "The number of sampled read queries by command name."
strict: false
fields:
total:
type: long
validator: { gte: 0 }
default: 0
find:
type: long
validator: { gte: 0 }
default: 0
aggregate:
type: long
validator: { gte: 0 }
default: 0
count:
type: long
validator: { gte: 0 }
default: 0
distinct:
type: long
validator: { gte: 0 }
default: 0
WriteSampleSize:
description: "The number of sampled write queries by command name."
strict: false
fields:
total:
type: long
validator: { gte: 0 }
default: 0
update:
type: long
validator: { gte: 0 }
default: 0
delete:
type: long
validator: { gte: 0 }
default: 0
findAndModify:
type: long
validator: { gte: 0 }
default: 0
ReadDistributionMetrics:
description: "The metrics about the read distribution calculated using sampled read queries."
strict: true
fields:
sampleSize:
type: ReadSampleSize
numSingleShardReads:
type: long
cpp_name: numSingleShard
validator: { gte: 0 }
optional: true
percentageOfSingleShardReads:
type: double
cpp_name: percentageOfSingleShard
validator:
gte: 0
lte: 100
optional: true
numMultiShardReads:
type: long
cpp_name: numMultiShard
validator: { gte: 0 }
optional: true
percentageOfMultiShardReads:
type: double
cpp_name: percentageOfMultiShard
validator:
gte: 0
lte: 100
optional: true
numScatterGatherReads:
type: long
cpp_name: numScatterGather
validator: { gte: 0 }
optional: true
percentageOfScatterGatherReads:
type: double
cpp_name: percentageOfScatterGather
validator:
gte: 0
lte: 100
optional: true
numReadsByRange:
type: array<long>
cpp_name: numByRange
description: "The number of dispatched read requests for each chunk range sorted from
MinKey to MaxKey."
optional: true
WriteDistributionMetrics:
description: "The metrics about the write distribution calculated using sampled write queries."
strict: true
fields:
sampleSize:
type: WriteSampleSize
numSingleShardWrites:
type: long
cpp_name: numSingleShard
validator: { gte: 0 }
optional: true
percentageOfSingleShardWrites:
type: double
cpp_name: percentageOfSingleShard
validator:
gte: 0
lte: 100
optional: true
numMultiShardWrites:
type: long
cpp_name: numMultiShard
validator: { gte: 0 }
optional: true
percentageOfMultiShardWrites:
type: double
cpp_name: percentageOfMultiShard
validator:
gte: 0
lte: 100
optional: true
numScatterGatherWrites:
type: long
cpp_name: numScatterGather
validator: { gte: 0 }
optional: true
percentageOfScatterGatherWrites:
type: double
cpp_name: percentageOfScatterGather
validator:
gte: 0
lte: 100
optional: true
numWritesByRange:
type: array<long>
cpp_name: numByRange
description: "The number of dispatched write requests for each chunk range sorted from
MinKey to MaxKey."
optional: true
numShardKeyUpdates:
type: long
validator: { gte: 0 }
optional: true
percentageOfShardKeyUpdates:
type: double
validator:
gte: 0
lte: 100
optional: true
numSingleWritesWithoutShardKey:
type: long
validator: { gte: 0 }
optional: true
percentageOfSingleWritesWithoutShardKey:
type: double
validator:
gte: 0
lte: 100
optional: true
numMultiWritesWithoutShardKey:
type: long
validator: { gte: 0 }
optional: true
percentageOfMultiWritesWithoutShardKey:
type: double
validator:
gte: 0
lte: 100
optional: true
analyzeShardKeyResponse:
description: "The response for the 'analyzeShardKey' command."
strict: false
inline_chained_structs: true
chained_structs:
KeyCharacteristicsMetrics: keyCharacteristics
fields:
readDistribution:
type: ReadDistributionMetrics
optional: true
writeDistribution:
type: WriteDistributionMetrics
optional: true
note:
description: "The note about how to interpret the metrics."
type: string
optional: true
commands:
analyzeShardKey:
description: "The command for calculating metrics for evaluating a shard key for a collection."
command_name: analyzeShardKey
strict: false
namespace: type
api_version: ""
type: namespacestring
fields:
key:
type: KeyPattern
description: "The shard key to evaluate."
validator:
callback: validateShardKeyPattern
$readPreference:
type: readPreference
cpp_name: readPreference
description: >-
The read preference to use for metrics calculation. The default is set to
"secondaryPreferred" to minimize the impact on user workloads.
default: ReadPreferenceSetting{ReadPreference::SecondaryPreferred}
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