heron/common/src/python/constants.py - incubator-heron - Git at Google

 # Copyright 2016 Twitter. All rights reserved.
 #
 # 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.
 ''' constants.py: defines constants for generic purposes and for topology and system config'''

 ##### Generic constants #####

 KB = 1024
 MB = 1024 * KB
 GB = 1024 * MB

 MS_TO_SEC = 0.001
 SEC_TO_NS = 1000000000
 NS_TO_MS = 0.000001

 RAM_FOR_STMGR = 1 * GB
 DEFAULT_RAM_FOR_INSTANCE = 1 * GB
 DEFAULT_DISK_PADDING_PER_CONTAINER = 12 * GB

 ####################################################################################################
 ###########################  Constants for topology configuration ##################################
 ####################################################################################################

 # Topology-specific options for the worker child process.
 TOPOLOGY_WORKER_CHILDOPTS = "topology.worker.childopts"
 # Per component jvm options.
 TOPOLOGY_COMPONENT_JVMOPTS = "topology.component.jvmopts"
 # How often a tick tuple from the "__system" component and "__tick" stream should be sent to tasks.
 TOPOLOGY_TICK_TUPLE_FREQ_SECS = "topology.tick.tuple.freq.secs"
 # True if Heron should timeout messages or not. Default true. Meant to be used in unit tests.
 TOPOLOGY_ENABLE_MESSAGE_TIMEOUTS = "topology.enable.message.timeouts"
 # When true, Heron will log every message that's emitted
 TOPOLOGY_DEBUG = "topology.debug"
 # The number of stmgr instances that should spin up to service this topology.
 TOPOLOGY_STMGRS = "topology.stmgrs"
 # The max amount of time given to the topology to fully process a message emitted by a spout.
 TOPOLOGY_MESSAGE_TIMEOUT_SECS = "topology.message.timeout.secs"
 # The per component parallelism for a component in this topology.
 TOPOLOGY_COMPONENT_PARALLELISM = "topology.component.parallelism"
 # The maximum number of tuples that can be pending on a spout task at any given time.
 TOPOLOGY_MAX_SPOUT_PENDING = "topology.max.spout.pending"
 # A list of task hooks that are automatically added to every spout and bolt in the topology.
 TOPOLOGY_AUTO_TASK_HOOKS = "topology.auto.task.hooks"
 # The serialization class that is used to serialize/deserialize tuples
 TOPOLOGY_SERIALIZER_CLASSNAME = "topology.serializer.classname"
 # How many executors to spawn for ackers.
 TOPOLOGY_ENABLE_ACKING = "topology.acking"

 # Number of cpu cores per container to be reserved for this topology.
 TOPOLOGY_CONTAINER_CPU_REQUESTED = "topology.container.cpu"
 # Amount of ram per container to be reserved for this topology, in bytes.
 TOPOLOGY_CONTAINER_RAM_REQUESTED = "topology.container.ram"
 # Amount of disk per container to be reserved for this topology, in bytes.
 TOPOLOGY_CONTAINER_DISK_REQUESTED = "topology.container.disk"
 # Hint for max amount of ram per container to be reserved for this topology, in bytes.
 TOPOLOGY_CONTAINER_MAX_CPU_HINT = "topology.container.max.cpu.hint"
 # Hint for max amount of disk per container to be reserved for this topology, in bytes.
 TOPOLOGY_CONTAINER_MAX_DISK_HINT = "topology.container.max.disk.hint"
 # Padding percentage for this container.
 TOPOLOGY_CONTAINER_PADDING_PERCENTAGE = "topology.container.padding.percentage"

 # Per component ram requirement.
 TOPOLOGY_COMPONENT_RAMMAP = "topology.component.rammap"
 # Name of the topology, automatically set by Heron when the topology is submitted.
 TOPOLOGY_NAME = "topology.name"
 # Name of the team which owns this topology.
 TOPOLOGY_TEAM_NAME = "topology.team.name"
 # Email of the team which owns this topology.
 TOPOLOGY_TEAM_EMAIL = "topology.team.email"
 # Cap ticket (if filed) for the topology. If the topology is in prod, this has to be set or it
 # cannot be deployed.
 TOPOLOGY_CAP_TICKET = "topology.cap.ticket"
 # Project name of the topology, to help us with tagging which topologies are part of which project.
 TOPOLOGY_PROJECT_NAME = "topology.project.name"
 # Any user defined classpath that needs to be passed to instances should be set in to config
 # through this key.
 TOPOLOGY_ADDITIONAL_CLASSPATH = "topology.additional.classpath"


 ####################################################################################################
 #############################  Constants for System configuration ##################################
 ####################################################################################################

 # The relative path to the logging directory
 HERON_LOGGING_DIRECTORY = 'heron.logging.directory'
 # The maximum log file size in MB
 HERON_LOGGING_MAXIMUM_SIZE_MB = "heron.logging.maximum.size.mb"
 # The maximum number of log files
 HERON_LOGGING_MAXIMUM_FILES = "heron.logging.maximum.files"
 # The threshold level to log error
 HERON_LOGGING_ERR_THRESHOLD = "heron.logging.err.threshold"
 # The interval in seconds to get and reset the system metrics.
 HERON_METRICS_EXPORT_INTERVAL_SEC = "heron.metrics.export.interval.sec"

 ####################################################################################################
 ############################### Sytem config: Instance related #####################################
 ####################################################################################################

 # The queue capacity (num of items) in bolt for buffer packets to read from stream manager
 INSTANCE_INTERNAL_BOLT_READ_QUEUE_CAPACITY = "heron.instance.internal.bolt.read.queue.capacity"
 # The queue capacity (num of items) in bolt for buffer packets to write to stream manager
 INSTANCE_INTERNAL_BOLT_WRITE_QUEUE_CAPACITY = "heron.instance.internal.bolt.write.queue.capacity"
 # The queue capacity (num of items) in spout for buffer packets to read from stream manager
 INSTANCE_INTERNAL_SPOUT_READ_QUEUE_CAPACITY = "heron.instance.internal.spout.read.queue.capacity"
 # The queue capacity (num of items) in spout for buffer packets to write to stream manager
 INSTANCE_INTERNAL_SPOUT_WRITE_QUEUE_CAPACITY = "heron.instance.internal.spout.write.queue.capacity"
 # The queue capacity (num of items) for metrics packets to write to metrics manager
 INSTANCE_INTERNAL_METRICS_WRITE_QUEUE_CAPACITY = \
   "heron.instance.internal.metrics.write.queue.capacity"

 # Time based, the maximum batch time in ms for instance to read from stream manager per attempt
 INSTANCE_NETWORK_READ_BATCH_TIME_MS = "heron.instance.network.read.batch.time.ms"
 # Size based, the maximum batch size in bytes to read from stream manager
 INSTANCE_NETWORK_READ_BATCH_SIZE_BYTES = "heron.instance.network.read.batch.size.bytes"
 # Time based, the maximum batch time in ms for instance to write to stream manager per attempt
 INSTANCE_NETWORK_WRITE_BATCH_TIME_MS = "heron.instance.network.write.batch.time.ms"
 # Size based, the maximum batch size in bytes to write to stream manager
 INSTANCE_NETWORK_WRITE_BATCH_SIZE_BYTES = "heron.instance.network.write.batch.size.bytes"
 # The maximum socket's received buffer size in bytes of instance's network options
 INSTANCE_NETWORK_OPTIONS_SOCKET_RECEIVED_BUFFER_SIZE_BYTES = \
   "heron.instance.network.options.socket.received.buffer.size.bytes"
 # The maximum socket's send buffer size in bytes
 INSTANCE_NETWORK_OPTIONS_SOCKET_SEND_BUFFER_SIZE_BYTES = \
   "heron.instance.network.options.socket.send.buffer.size.bytes"

 # The maximum # of data tuple to batch in a HeronDataTupleSet protobuf
 INSTANCE_SET_DATA_TUPLE_CAPACITY = "heron.instance.set.data.tuple.capacity"
 # The maximum size in bytes of data tuple to batch in a HeronDataTupleSet protobuf
 INSTANCE_SET_DATA_TUPLE_SIZE_BYTES = "heron.instance.set.data.tuple.size.bytes"

 # The maximum # of control tuple to batch in a HeronControlTupleSet protobuf
 INSTANCE_SET_CONTROL_TUPLE_CAPACITY = "heron.instance.set.control.tuple.capacity"
 # The maximum time in ms for an spout to do acknowledgement per attempt
 INSTANCE_ACK_BATCH_TIME_MS = "heron.instance.ack.batch.time.ms"
 # The maximum time in ms for an spout instance to emit tuples per attempt
 INSTANCE_EMIT_BATCH_TIME_MS = "heron.instance.emit.batch.time.ms"
 # The maximum batch size in bytes for an spout instance to emit tuples per attempt
 INSTANCE_EMIT_BATCH_SIZE_BYTES = "heron.instance.emit.batch.size.bytes"
 # The maximum time in ms for an bolt instance to execute tuples per attempt
 INSTANCE_EXECUTE_BATCH_TIME_MS = "heron.instance.execute.batch.time.ms"
 # The maximum batch size in bytes for an bolt instance to execute tuples per attempt
 INSTANCE_EXECUTE_BATCH_SIZE_BYTES = "heron.instance.execute.batch.size.bytes"

 # The time to wait before the instance exits forcibly when uncaught exception happens
 INSTANCE_FORCE_EXIT_TIMEOUT_MS = "heron.instance.force.exit.timeout.ms"
 # Interval in seconds to reconnect to the stream manager
 INSTANCE_RECONNECT_STREAMMGR_INTERVAL_SEC = "heron.instance.reconnect.streammgr.interval.sec"
 # Interval in seconds to reconnect to the metrics manager
 INSTANCE_RECONNECT_METRICSMGR_INTERVAL_SEC = "heron.instance.reconnect.metricsmgr.interval.sec"
 # Interval in seconds to sample a system metric, for instance, jvm used memory.
 INSTANCE_METRICS_SYSTEM_SAMPLE_INTERVAL_SEC = "heron.instance.metrics.system.sample.interval.sec"

 # The lookForTimeout Interval in spout instance will be timeoutInSeconds / NBUCKETS
 # For instance, if a tuple's timeout is 30s, and NBUCKETS is 10
 # The spout instance will check whether there are timeout tuples every 3 seconds
 INSTANCE_ACKNOWLEDGEMENT_NBUCKETS = "heron.instance.acknowledgement.nbuckets"

 # The expected size on read queue in bolt
 INSTANCE_TUNING_EXPECTED_BOLT_READ_QUEUE_SIZE \
   = "heron.instance.tuning.expected.bolt.read.queue.size"
 # The expected size on write queue in bolt
 INSTANCE_TUNING_EXPECTED_BOLT_WRITE_QUEUE_SIZE \
   = "heron.instance.tuning.expected.bolt.write.queue.size"
 # The expected size on read queue in spout
 INSTANCE_TUNING_EXPECTED_SPOUT_READ_QUEUE_SIZE \
   = "heron.instance.tuning.expected.spout.read.queue.size"
 # The exepected size on write queue in spout
 INSTANCE_TUNING_EXPECTED_SPOUT_WRITE_QUEUE_SIZE \
   = "heron.instance.tuning.expected.spout.write.queue.size"
 # The expected size on metrics write queue
 INSTANCE_TUNING_EXPECTED_METRICS_WRITE_QUEUE_SIZE \
   = "heron.instance.tuning.expected.metrics.write.queue.size"

 # During dynamically tuning, the weight of new sample size to calculate
 # the available capacity of queue.
 # We use Exponential moving average: En = (1-w) * En-1 + w * An
 # http://en.wikipedia.org/wiki/Moving_average#Exponential_moving_average
 INSTANCE_TUNING_CURRENT_SAMPLE_WEIGHT = "heron.instance.tuning.current.sample.weight"

 # Interval in ms to tune the size of in &amp; out data queue in instance
 INSTANCE_TUNING_INTERVAL_MS = "heron.instance.tuning.interval.ms"

 ####################################################################################################
 ########################### Sytem config: Metrics Manager related ##################################
 ####################################################################################################

 # Time based, the maximum batch time in ms for instance to read from socket per attempt
 METRICSMGR_NETWORK_READ_BATCH_TIME_MS = "heron.metricsmgr.network.read.batch.time.ms"
 # Size based,the maximum batch size in bytes to read from socket
 METRICSMGR_NETWORK_READ_BATCH_SIZE_BYTES = "heron.metricsmgr.network.read.batch.size.bytes"
 # Time based, the maximum batch time in ms to write to socket
 METRICSMGR_NETWORK_WRITE_BATCH_TIME_MS = "heron.metricsmgr.network.write.batch.time.ms"
 # Size based, the maximum batch size in bytes to write to socket
 METRICSMGR_NETWORK_WRITE_BATCH_SIZE_BYTES = "heron.metricsmgr.network.write.batch.size.bytes"
 # The maximum socket's received buffer size in bytes
 METRICSMGR_NETWORK_OPTIONS_SOCKET_RECEIVED_BUFFER_SIZE_BYTES \
   = "heron.metricsmgr.network.options.socket.received.buffer.size.bytes"
 # The maximum socket's send buffer size in bytes
 METRICSMGR_NETWORK_OPTIONS_SOCKET_SEND_BUFFER_SIZE_BYTES \
   = "heron.metricsmgr.network.options.socket.send.buffer.size.bytes"
	# Copyright 2016 Twitter. All rights reserved.
	#
	# 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.
	''' constants.py: defines constants for generic purposes and for topology and system config'''

	##### Generic constants #####

	KB = 1024
	MB = 1024 * KB
	GB = 1024 * MB

	MS_TO_SEC = 0.001
	SEC_TO_NS = 1000000000
	NS_TO_MS = 0.000001

	RAM_FOR_STMGR = 1 * GB
	DEFAULT_RAM_FOR_INSTANCE = 1 * GB
	DEFAULT_DISK_PADDING_PER_CONTAINER = 12 * GB

	####################################################################################################
	########################### Constants for topology configuration ##################################
	####################################################################################################

	# Topology-specific options for the worker child process.
	TOPOLOGY_WORKER_CHILDOPTS = "topology.worker.childopts"
	# Per component jvm options.
	TOPOLOGY_COMPONENT_JVMOPTS = "topology.component.jvmopts"
	# How often a tick tuple from the "__system" component and "__tick" stream should be sent to tasks.
	TOPOLOGY_TICK_TUPLE_FREQ_SECS = "topology.tick.tuple.freq.secs"
	# True if Heron should timeout messages or not. Default true. Meant to be used in unit tests.
	TOPOLOGY_ENABLE_MESSAGE_TIMEOUTS = "topology.enable.message.timeouts"
	# When true, Heron will log every message that's emitted
	TOPOLOGY_DEBUG = "topology.debug"
	# The number of stmgr instances that should spin up to service this topology.
	TOPOLOGY_STMGRS = "topology.stmgrs"
	# The max amount of time given to the topology to fully process a message emitted by a spout.
	TOPOLOGY_MESSAGE_TIMEOUT_SECS = "topology.message.timeout.secs"
	# The per component parallelism for a component in this topology.
	TOPOLOGY_COMPONENT_PARALLELISM = "topology.component.parallelism"
	# The maximum number of tuples that can be pending on a spout task at any given time.
	TOPOLOGY_MAX_SPOUT_PENDING = "topology.max.spout.pending"
	# A list of task hooks that are automatically added to every spout and bolt in the topology.
	TOPOLOGY_AUTO_TASK_HOOKS = "topology.auto.task.hooks"
	# The serialization class that is used to serialize/deserialize tuples
	TOPOLOGY_SERIALIZER_CLASSNAME = "topology.serializer.classname"
	# How many executors to spawn for ackers.
	TOPOLOGY_ENABLE_ACKING = "topology.acking"

	# Number of cpu cores per container to be reserved for this topology.
	TOPOLOGY_CONTAINER_CPU_REQUESTED = "topology.container.cpu"
	# Amount of ram per container to be reserved for this topology, in bytes.
	TOPOLOGY_CONTAINER_RAM_REQUESTED = "topology.container.ram"
	# Amount of disk per container to be reserved for this topology, in bytes.
	TOPOLOGY_CONTAINER_DISK_REQUESTED = "topology.container.disk"
	# Hint for max amount of ram per container to be reserved for this topology, in bytes.
	TOPOLOGY_CONTAINER_MAX_CPU_HINT = "topology.container.max.cpu.hint"
	# Hint for max amount of disk per container to be reserved for this topology, in bytes.
	TOPOLOGY_CONTAINER_MAX_DISK_HINT = "topology.container.max.disk.hint"
	# Padding percentage for this container.
	TOPOLOGY_CONTAINER_PADDING_PERCENTAGE = "topology.container.padding.percentage"

	# Per component ram requirement.
	TOPOLOGY_COMPONENT_RAMMAP = "topology.component.rammap"
	# Name of the topology, automatically set by Heron when the topology is submitted.
	TOPOLOGY_NAME = "topology.name"
	# Name of the team which owns this topology.
	TOPOLOGY_TEAM_NAME = "topology.team.name"
	# Email of the team which owns this topology.
	TOPOLOGY_TEAM_EMAIL = "topology.team.email"
	# Cap ticket (if filed) for the topology. If the topology is in prod, this has to be set or it
	# cannot be deployed.
	TOPOLOGY_CAP_TICKET = "topology.cap.ticket"
	# Project name of the topology, to help us with tagging which topologies are part of which project.
	TOPOLOGY_PROJECT_NAME = "topology.project.name"
	# Any user defined classpath that needs to be passed to instances should be set in to config
	# through this key.
	TOPOLOGY_ADDITIONAL_CLASSPATH = "topology.additional.classpath"


	####################################################################################################
	############################# Constants for System configuration ##################################
	####################################################################################################

	# The relative path to the logging directory
	HERON_LOGGING_DIRECTORY = 'heron.logging.directory'
	# The maximum log file size in MB
	HERON_LOGGING_MAXIMUM_SIZE_MB = "heron.logging.maximum.size.mb"
	# The maximum number of log files
	HERON_LOGGING_MAXIMUM_FILES = "heron.logging.maximum.files"
	# The threshold level to log error
	HERON_LOGGING_ERR_THRESHOLD = "heron.logging.err.threshold"
	# The interval in seconds to get and reset the system metrics.
	HERON_METRICS_EXPORT_INTERVAL_SEC = "heron.metrics.export.interval.sec"

	####################################################################################################
	############################### Sytem config: Instance related #####################################
	####################################################################################################

	# The queue capacity (num of items) in bolt for buffer packets to read from stream manager
	INSTANCE_INTERNAL_BOLT_READ_QUEUE_CAPACITY = "heron.instance.internal.bolt.read.queue.capacity"
	# The queue capacity (num of items) in bolt for buffer packets to write to stream manager
	INSTANCE_INTERNAL_BOLT_WRITE_QUEUE_CAPACITY = "heron.instance.internal.bolt.write.queue.capacity"
	# The queue capacity (num of items) in spout for buffer packets to read from stream manager
	INSTANCE_INTERNAL_SPOUT_READ_QUEUE_CAPACITY = "heron.instance.internal.spout.read.queue.capacity"
	# The queue capacity (num of items) in spout for buffer packets to write to stream manager
	INSTANCE_INTERNAL_SPOUT_WRITE_QUEUE_CAPACITY = "heron.instance.internal.spout.write.queue.capacity"
	# The queue capacity (num of items) for metrics packets to write to metrics manager
	INSTANCE_INTERNAL_METRICS_WRITE_QUEUE_CAPACITY = \
	"heron.instance.internal.metrics.write.queue.capacity"

	# Time based, the maximum batch time in ms for instance to read from stream manager per attempt
	INSTANCE_NETWORK_READ_BATCH_TIME_MS = "heron.instance.network.read.batch.time.ms"
	# Size based, the maximum batch size in bytes to read from stream manager
	INSTANCE_NETWORK_READ_BATCH_SIZE_BYTES = "heron.instance.network.read.batch.size.bytes"
	# Time based, the maximum batch time in ms for instance to write to stream manager per attempt
	INSTANCE_NETWORK_WRITE_BATCH_TIME_MS = "heron.instance.network.write.batch.time.ms"
	# Size based, the maximum batch size in bytes to write to stream manager
	INSTANCE_NETWORK_WRITE_BATCH_SIZE_BYTES = "heron.instance.network.write.batch.size.bytes"
	# The maximum socket's received buffer size in bytes of instance's network options
	INSTANCE_NETWORK_OPTIONS_SOCKET_RECEIVED_BUFFER_SIZE_BYTES = \
	"heron.instance.network.options.socket.received.buffer.size.bytes"
	# The maximum socket's send buffer size in bytes
	INSTANCE_NETWORK_OPTIONS_SOCKET_SEND_BUFFER_SIZE_BYTES = \
	"heron.instance.network.options.socket.send.buffer.size.bytes"

	# The maximum # of data tuple to batch in a HeronDataTupleSet protobuf
	INSTANCE_SET_DATA_TUPLE_CAPACITY = "heron.instance.set.data.tuple.capacity"
	# The maximum size in bytes of data tuple to batch in a HeronDataTupleSet protobuf
	INSTANCE_SET_DATA_TUPLE_SIZE_BYTES = "heron.instance.set.data.tuple.size.bytes"

	# The maximum # of control tuple to batch in a HeronControlTupleSet protobuf
	INSTANCE_SET_CONTROL_TUPLE_CAPACITY = "heron.instance.set.control.tuple.capacity"
	# The maximum time in ms for an spout to do acknowledgement per attempt
	INSTANCE_ACK_BATCH_TIME_MS = "heron.instance.ack.batch.time.ms"
	# The maximum time in ms for an spout instance to emit tuples per attempt
	INSTANCE_EMIT_BATCH_TIME_MS = "heron.instance.emit.batch.time.ms"
	# The maximum batch size in bytes for an spout instance to emit tuples per attempt
	INSTANCE_EMIT_BATCH_SIZE_BYTES = "heron.instance.emit.batch.size.bytes"
	# The maximum time in ms for an bolt instance to execute tuples per attempt
	INSTANCE_EXECUTE_BATCH_TIME_MS = "heron.instance.execute.batch.time.ms"
	# The maximum batch size in bytes for an bolt instance to execute tuples per attempt
	INSTANCE_EXECUTE_BATCH_SIZE_BYTES = "heron.instance.execute.batch.size.bytes"

	# The time to wait before the instance exits forcibly when uncaught exception happens
	INSTANCE_FORCE_EXIT_TIMEOUT_MS = "heron.instance.force.exit.timeout.ms"
	# Interval in seconds to reconnect to the stream manager
	INSTANCE_RECONNECT_STREAMMGR_INTERVAL_SEC = "heron.instance.reconnect.streammgr.interval.sec"
	# Interval in seconds to reconnect to the metrics manager
	INSTANCE_RECONNECT_METRICSMGR_INTERVAL_SEC = "heron.instance.reconnect.metricsmgr.interval.sec"
	# Interval in seconds to sample a system metric, for instance, jvm used memory.
	INSTANCE_METRICS_SYSTEM_SAMPLE_INTERVAL_SEC = "heron.instance.metrics.system.sample.interval.sec"

	# The lookForTimeout Interval in spout instance will be timeoutInSeconds / NBUCKETS
	# For instance, if a tuple's timeout is 30s, and NBUCKETS is 10
	# The spout instance will check whether there are timeout tuples every 3 seconds
	INSTANCE_ACKNOWLEDGEMENT_NBUCKETS = "heron.instance.acknowledgement.nbuckets"

	# The expected size on read queue in bolt
	INSTANCE_TUNING_EXPECTED_BOLT_READ_QUEUE_SIZE \
	= "heron.instance.tuning.expected.bolt.read.queue.size"
	# The expected size on write queue in bolt
	INSTANCE_TUNING_EXPECTED_BOLT_WRITE_QUEUE_SIZE \
	= "heron.instance.tuning.expected.bolt.write.queue.size"
	# The expected size on read queue in spout
	INSTANCE_TUNING_EXPECTED_SPOUT_READ_QUEUE_SIZE \
	= "heron.instance.tuning.expected.spout.read.queue.size"
	# The exepected size on write queue in spout
	INSTANCE_TUNING_EXPECTED_SPOUT_WRITE_QUEUE_SIZE \
	= "heron.instance.tuning.expected.spout.write.queue.size"
	# The expected size on metrics write queue
	INSTANCE_TUNING_EXPECTED_METRICS_WRITE_QUEUE_SIZE \
	= "heron.instance.tuning.expected.metrics.write.queue.size"

	# During dynamically tuning, the weight of new sample size to calculate
	# the available capacity of queue.
	# We use Exponential moving average: En = (1-w) * En-1 + w * An
	# http://en.wikipedia.org/wiki/Moving_average#Exponential_moving_average
	INSTANCE_TUNING_CURRENT_SAMPLE_WEIGHT = "heron.instance.tuning.current.sample.weight"

	# Interval in ms to tune the size of in & out data queue in instance
	INSTANCE_TUNING_INTERVAL_MS = "heron.instance.tuning.interval.ms"

	####################################################################################################
	########################### Sytem config: Metrics Manager related ##################################
	####################################################################################################

	# Time based, the maximum batch time in ms for instance to read from socket per attempt
	METRICSMGR_NETWORK_READ_BATCH_TIME_MS = "heron.metricsmgr.network.read.batch.time.ms"
	# Size based,the maximum batch size in bytes to read from socket
	METRICSMGR_NETWORK_READ_BATCH_SIZE_BYTES = "heron.metricsmgr.network.read.batch.size.bytes"
	# Time based, the maximum batch time in ms to write to socket
	METRICSMGR_NETWORK_WRITE_BATCH_TIME_MS = "heron.metricsmgr.network.write.batch.time.ms"
	# Size based, the maximum batch size in bytes to write to socket
	METRICSMGR_NETWORK_WRITE_BATCH_SIZE_BYTES = "heron.metricsmgr.network.write.batch.size.bytes"
	# The maximum socket's received buffer size in bytes
	METRICSMGR_NETWORK_OPTIONS_SOCKET_RECEIVED_BUFFER_SIZE_BYTES \
	= "heron.metricsmgr.network.options.socket.received.buffer.size.bytes"
	# The maximum socket's send buffer size in bytes
	METRICSMGR_NETWORK_OPTIONS_SOCKET_SEND_BUFFER_SIZE_BYTES \
	= "heron.metricsmgr.network.options.socket.send.buffer.size.bytes"