AMQP 0-9-1 Model Explained Why does the queue memory grow and shrink when publishing/consuming? AMQP和AMQP Protocol的是整体和部分的关系 RabbitMQ speaks multiple protocols.
AMQP 0-9-1 Model Explained — RabbitMQ http://next.rabbitmq.com/tutorials/amqp-concepts.html
AMQP 0-9-1 Model Explained
About This Guide
This guide provides an overview of the the AMQP 0-9-1 protocol, one of the protocols supported by RabbitMQ.
High-level Overview of AMQP 0-9-1 and the AMQP Model
What is AMQP 0-9-1?
AMQP 0-9-1 (Advanced Message Queuing Protocol) is a messaging protocol that enables conforming client applications to communicate with conforming messaging middleware brokers.
Brokers and Their Role
Messaging brokers receive messages from publishers (applications that publish them, also known as producers) and route them to consumers (applications that process them).
Since it is a network protocol, the publishers, consumers and the broker can all reside on different machines.
AMQP 0-9-1 Model in Brief
The AMQP 0-9-1 Model has the following view of the world: messages are published toexchanges, which are often compared to post offices or mailboxes. Exchanges then distribute message copies to queues using rules called bindings. Then AMQP brokers either deliver messages to consumers subscribed to queues, or consumers fetch/pull messages from queues on demand.
publisher发布者--->messages消息--->exchages邮局,信箱---->queues队列 ...consumers消费者
exchange邮局按照一定的规则rules/bindings将消息message复制copy到队列queue
AMQPbrokers将消息发送deliver给订阅队列queue的消费者consumer
或者
消费者consumer按照需要on demand去拉取fetch/pull消息messages
【对代理不透明部分】
消息的元数据中对代理brocker:透明opaque、不透明部分
When publishing a message, publishers may specify various message attributes (message meta-data). Some of this meta-data may be used by the broker, however, the rest of it is completely opaque to the broker and is only used by applications that receive the message.
【message acknowledgements】
消费者在收到消息后,可以发送消息确认,也可以不发送;如发送,则代理broker将消息从队列中删除remove
Networks are unreliable and applications may fail to process messages therefore the AMQP model has a notion of message acknowledgements: when a message is delivered to a consumer the consumer notifies the broker, either automatically or as soon as the application developer chooses to do so. When message acknowledgements are in use, a broker will only completely remove a message from a queue when it receives a notification for that message (or group of messages).
【没有接收路由的情况dead letter queue】
在消息message不能被路由routed的情况下,消息被broker投入死信队列dead letter queue;这种情况的处理由发布者publisher决定
In certain situations, for example, when a message cannot be routed, messages may bereturned to publishers, dropped, or, if the broker implements an extension, placed into a so-called "dead letter queue". Publishers choose how to handle situations like this by publishing messages using certain parameters.
Queues, exchanges and bindings are collectively referred to as AMQP entities.
【Queues, exchanges and bindings are collectively referred to as AMQP entities】
AMQP is a Programmable Protocol
AMQP 0-9-1 is a programmable protocol in the sense that AMQP 0-9-1 entities and routing schemes are primarily defined by applications themselves, not a broker administrator. Accordingly, provision is made for protocol operations that declare queues and exchanges, define bindings between them, subscribe to queues and so on.
This gives application developers a lot of freedom but also requires them to be aware of potential definition conflicts. In practice, definition conflicts are rare and often indicate a misconfiguration.
【删除邮局、队列的理论依据】
Applications declare the AMQP 0-9-1 entities that they need, define necessary routing schemes and may choose to delete AMQP 0-9-1 entities when they are no longer used.
【协议是国际标准】
Home | AMQP http://www.amqp.org/
Advanced Message Queuing Protocol 1.0 approved as an International Standard
Click above for the press release. The International Standard (ISO/IEC 19464) can be down loadedhere.
See this presentation to learn more about AMQP and its value.
Advanced Message Queuing Protocol 1.0 becomes OASIS Standard
Click above for the press release. The Standard can be down loaded here.
See the executive briefing paper on the value proposition of OASIS AMQP to learn more.
AMQP_百度百科 https://baike.baidu.com/item/AMQP/8354716?fr=aladdin
【动手所得】
1、流程启动server;
2、配置用户权限;
3、外网/内网发布、接收消息;
systemctl start rabbitmq-server
/是rabbitmq默认的虚拟机,之前默认连接的都是它
创建一个用户
rabbitmqctl add_user username password
为用户分配角色
rabbitmqctl set_user_tags username administrator
#Tags 可以是:administrator, monitoring, management
设置访问权限
rabbitmqctl set_permissions -p vhostname username ".*" ".*" ".*"
【文档】
http://www.rabbitmq.com/admin-guide.html
http://www.rabbitmq.com/clients.html
http://www.rabbitmq.com/man/rabbitmqctl.8.html http://www.rabbitmq.com/man/rabbitmqctl.8.html
NAME
rabbitmqctl — command line for managing a RabbitMQ broker
SYNOPSIS
rabbitmqctl | [-q] [-l] [-n node] [-t timeout] command [command_options] |
DESCRIPTION
RabbitMQ is a multi-protocol open source messaging broker.
rabbitmqctl is a command line tool for managing a RabbitMQ broker. It performs all actions by connecting to one of the broker's nodes.
Diagnostic information is displayed if the broker was not running, could not be reached, or rejected the connection due to mismatching Erlang cookies.
OPTIONS
- -n node
- Default node is “rabbit@server”, where server is the local host. On a host named “myserver.example.com”, the node name of the RabbitMQ Erlang node will usually be “rabbit@myserver” (unless
RABBITMQ_NODENAME
has been set to some non-default value at broker startup time). The output of “hostname -s” is usually the correct suffix to use after the “@” sign. See rabbitmq-server(8) for details of configuring the RabbitMQ broker. - -q, --quiet
- Quiet output mode is selected. Informational messages are suppressed when quiet mode is in effect.
- --dry-run
- Do not run the command. Only print information message.
- -t timeout, --timeout timeout
- Operation timeout in seconds. Only applicable to “list” commands. Default is infinity.
- -l, --longnames
- Use longnames for erlang distribution. If RabbitMQ broker uses long node names for erlang distribution, the option must be specified.
- --erlang-cookie cookie
- Erlang distribution cookie. If RabbitMQ node is using a custom erlang cookie value, the cookie value must be set vith this parameter.
COMMANDS
- help [-l] [command_name]
- Prints usage for all available commands.
- -l, --list-commands
- List command usages only, without parameter explanation.
- command_name
- Prints usage for the specified command.
Application Management
- force_reset
- Forcefully returns a RabbitMQ node to its virgin state.
rabbitmqctl force_reset
- hipe_compile directory
- Performs HiPE-compilation and caches resulting .beam-files in the given directory.
RABBITMQ_SERVER_CODE_PATH
environment variable to directory specified in hipe_compile invokation.rabbitmqctl hipe_compile /tmp/rabbit-hipe/ebin
- reset
- Returns a RabbitMQ node to its virgin state.
rabbitmqctl reset
- rotate_logs
- Instructs the RabbitMQ node to perform internal log rotation.
rabbitmqctl rotate_logs
- shutdown
- Shuts down the Erlang process on which RabbitMQ is running. The command is blocking and will return after the Erlang process exits. If RabbitMQ fails to stop, it will return a non-zero exit code.
- does not require a pid_file to wait for the Erlang process to exit
- returns a non-zero exit code if RabbitMQ node is not running
rabbitmqctl shutdown
- start_app
- Starts the RabbitMQ application.
rabbitmqctl start_app
- stop [pid_file]
- Stops the Erlang node on which RabbitMQ is running. To restart the node follow the instructions for “Running the Server” in the installation guide.
rabbitmqctl stop
- stop_app
- Stops the RabbitMQ application, leaving the Erlang node running.
rabbitmqctl stop_app
- wait pid_file, wait --pid pid
- Waits for the RabbitMQ application to start.
RABBITMQ_PID_FILE
environment variable to change the location.rabbitmqctl wait /var/run/rabbitmq/pid
Cluster Management
- join_cluster clusternode [--ram]
- clusternode
- Node to cluster with.
- --ram
- If provided, the node will join the cluster as a RAM node.
rabbitmqctl join_cluster hare@elena --ram
- cluster_status
- Displays all the nodes in the cluster grouped by node type, together with the currently running nodes.
rabbitmqctl cluster_status
- change_cluster_node_type type
- Changes the type of the cluster node.
rabbitmqctl change_cluster_node_type disc
- forget_cluster_node [--offline]
- --offline
- Enables node removal from an offline node. This is only useful in the situation where all the nodes are offline and the last node to go down cannot be brought online, thus preventing the whole cluster from starting. It should not be used in any other circumstances since it can lead to inconsistencies.
rabbitmqctl -n hare@mcnulty forget_cluster_node rabbit@stringer
- rename_cluster_node oldnode1 newnode1 [oldnode2 newnode2 ...]
- Supports renaming of cluster nodes in the local database.
rabbitmqctl rename_cluster_node rabbit@misshelpful rabbit@cordelia
- update_cluster_nodes clusternode
- clusternode
- The node to consult for up-to-date information.
update_cluster_nodes -n A C
- force_boot
- Ensures that the node will start next time, even if it was not the last to shut down.
rabbitmqctl force_boot
- sync_queue [-p vhost] queue
- queue
- The name of the queue to synchronise.
- cancel_sync_queue [-p vhost] queue
- queue
- The name of the queue to cancel synchronisation for.
- purge_queue [-p vhost] queue
- queue
- The name of the queue to purge.
- set_cluster_name name
- Sets the cluster name to name. The cluster name is announced to clients on connection, and used by the federation and shovel plugins to record where a message has been. The cluster name is by default derived from the hostname of the first node in the cluster, but can be changed.
rabbitmqctl set_cluster_name london
User Management
Note that rabbitmqctl manages the RabbitMQ internal user database. Users from any alternative authentication backend will not be visible to rabbitmqctl.
- add_user username password
- username
- The name of the user to create.
- password
- The password the created user will use to log in to the broker.
rabbitmqctl add_user tonyg changeit
- delete_user username
- username
- The name of the user to delete.
rabbitmqctl delete_user tonyg
- change_password username newpassword
- username
- The name of the user whose password is to be changed.
- newpassword
- The new password for the user.
rabbitmqctl change_password tonyg newpass
- clear_password username
- username
- The name of the user whose password is to be cleared.
rabbitmqctl clear_password tonyg
- authenticate_user username password
- username
- The name of the user.
- password
- The password of the user.
rabbitmqctl authenticate_user tonyg verifyit
- set_user_tags username [tag ...]
- username
- The name of the user whose tags are to be set.
- tag
- Zero, one or more tags to set. Any existing tags will be removed.
rabbitmqctl set_user_tags tonyg administrator
rabbitmqctl set_user_tags tonyg
- list_users
- Lists users. Each result row will contain the user name followed by a list of the tags set for that user.
rabbitmqctl list_users
Access Control
Note that rabbitmqctl manages the RabbitMQ internal user database. Permissions for users from any alternative authorisation backend will not be visible to rabbitmqctl.
- add_vhost vhost
- vhost
- The name of the virtual host entry to create.
rabbitmqctl add_vhost test
- delete_vhost vhost
- vhost
- The name of the virtual host entry to delete.
rabbitmqctl delete_vhost test
- list_vhosts [vhostinfoitem ...]
- Lists virtual hosts.
- name
- The name of the virtual host with non-ASCII characters escaped as in C.
- tracing
- Whether tracing is enabled for this virtual host.
rabbitmqctl list_vhosts name tracing
- set_permissions [-p vhost] user conf write read
- vhost
- The name of the virtual host to which to grant the user access, defaulting to “/”.
- user
- The name of the user to grant access to the specified virtual host.
- conf
- A regular expression matching resource names for which the user is granted configure permissions.
- write
- A regular expression matching resource names for which the user is granted write permissions.
- read
- A regular expression matching resource names for which the user is granted read permissions.
rabbitmqctl set_permissions -p /myvhost tonyg “^tonyg-.*” “.*” “.*”
- clear_permissions [-p vhost] username
- vhost
- The name of the virtual host to which to deny the user access, defaulting to “/”.
- username
- The name of the user to deny access to the specified virtual host.
rabbitmqctl clear_permissions -p /myvhost tonyg
- list_permissions [-p vhost]
- vhost
- The name of the virtual host for which to list the users that have been granted access to it, and their permissions. Defaults to “/”.
rabbitmqctl list_permissions -p /myvhost
- list_user_permissions username
- username
- The name of the user for which to list the permissions.
rabbitmqctl list_user_permissions tonyg
- set_topic_permissions [-p vhost] user exchange write read
- vhost
- The name of the virtual host to which to grant the user access, defaulting to “/”.
- user
- The name of the user the permissions apply to in the target virtual host.
- exchange
- The name of the topic exchange the authorisation check will be applied to.
- write
- A regular expression matching the routing key of the published message.
- read
- A regular expression matching the routing key of the consumed message.
rabbitmqctl set_topic_permissions -p /myvhost tonyg amq.topic “^tonyg-.*” “^tonyg-.*”
rabbitmqctl set_topic_permissions -p /myvhost tonyg amq.topic “^{username}-.*” “^{username}-.*”
- clear_topic_permissions [-p vhost] username [exchange]
- vhost
- The name of the virtual host to which to clear the topic permissions, defaulting to “/”.
- username
- The name of the user to clear topic permissions to the specified virtual host.
- exchange
- The name of the topic exchange to clear topic permissions, defaulting to all the topic exchanges the given user has topic permissions for.
rabbitmqctl clear_topic_permissions -p /myvhost tonyg amq.topic
- list_topic_permissions [-p vhost]
- vhost
- The name of the virtual host for which to list the users topic permissions. Defaults to “/”.
rabbitmqctl list_topic_permissions -p /myvhost
- list_user_topic_permissions username
- username
- The name of the user for which to list the topic permissions.
rabbitmqctl list_topic_user_permissions tonyg
Parameter Management
Certain features of RabbitMQ (such as the federation plugin) are controlled by dynamic, cluster-wide parameters. There are 2 kinds of parameters: parameters scoped to a virtual host and global parameters. Each vhost-scoped parameter consists of a component name, a name and a value. The component name and name are strings, and the value is an Erlang term. A global parameter consists of a name and value. The name is a string and the value is an Erlang term. Parameters can be set, cleared and listed. In general you should refer to the documentation for the feature in question to see how to set parameters.
- set_parameter [-p vhost] component_name name value
- Sets a parameter.
- component_name
- The name of the component for which the parameter is being set.
- name
- The name of the parameter being set.
- value
- The value for the parameter, as a JSON term. In most shells you are very likely to need to quote this.
rabbitmqctl set_parameter federation-upstream node01 '{"uri":"amqp://user:password@server/%2F","ack-mode":"on-publish"}'
- clear_parameter [-p vhost] component_name key
- Clears a parameter.
- component_name
- The name of the component for which the parameter is being cleared.
- name
- The name of the parameter being cleared.
rabbitmqctl clear_parameter federation-upstream node01
- list_parameters [-p vhost]
- Lists all parameters for a virtual host.
rabbitmqctl list_parameters
- set_global_parameter name value
- Sets a global runtime parameter. This is similar to set_parameter but the key-value pair isn't tied to a virtual host.
- name
- The name of the global runtime parameter being set.
- value
- The value for the global runtime parameter, as a JSON term. In most shells you are very likely to need to quote this.
rabbitmqctl set_global_parameter mqtt_default_vhosts '{"O=client,CN=guest":"/"}'
- clear_global_parameter name
- Clears a global runtime parameter. This is similar to clear_parameter but the key-value pair isn't tied to a virtual host.
- name
- The name of the global runtime parameter being cleared.
rabbitmqctl clear_global_parameter mqtt_default_vhosts
- list_global_parameters
- Lists all global runtime parameters. This is similar to list_parameters but the global runtime parameters are not tied to any virtual host.
rabbitmqctl list_global_parameters
Policy Management
Policies are used to control and modify the behaviour of queues and exchanges on a cluster-wide basis. Policies apply within a given vhost, and consist of a name, pattern, definition and an optional priority. Policies can be set, cleared and listed.
- set_policy [-p vhost] [--priority priority] [--apply-to apply-to] name pattern definition
- Sets a policy.
- name
- The name of the policy.
- pattern
- The regular expression, which when matches on a given resources causes the policy to apply.
- definition
- The definition of the policy, as a JSON term. In most shells you are very likely to need to quote this.
- priority
- The priority of the policy as an integer. Higher numbers indicate greater precedence. The default is 0.
- apply-to
- Which types of object this policy should apply to. Possible values are: The default is all ..
rabbitmqctl set_policy federate-me ^amq. '{"federation-upstream-set":"all"}'
- clear_policy [-p vhost] name
- Clears a policy.
- name
- The name of the policy being cleared.
rabbitmqctl clear_policy federate-me
- list_policies [-p vhost]
- Lists all policies for a virtual host.
rabbitmqctl list_policies
- set_operator_policy [-p vhost] [--priority priority] [--apply-to apply-to] name pattern definition
- Sets an operator policy that overrides a subset of arguments in user policies. Arguments are identical to those of set_policy.
- expires
- message-ttl
- max-length
- max-length-bytes
- clear_operator_policy [-p vhost] name
- Clears an operator policy. Arguments are identical to those of clear_policy.
- list_operator_policies [-p vhost]
- Lists operator policy overrides for a virtual host. Arguments are identical to those of list_policies.
Virtual Host Limits
It is possible to enforce certain limits on virtual hosts.
- set_vhost_limits [-p vhost] definition
- Sets virtual host limits.
- definition
- The definition of the limits, as a JSON term. In most shells you are very likely to need to quote this.
- max-connections
- max-queues
rabbitmqctl set_vhost_limits -p qa_env '{"max-connections": 64}'
rabbitmqctl set_vhost_limits -p qa_env '{"max-queues": 256}'
rabbitmqctl set_vhost_limits -p qa_env '{"max-connections": -1}'
rabbitmqctl set_vhost_limits -p qa_env '{"max-connections": 0}'
- clear_vhost_limits [-p vhost]
- Clears virtual host limits.
rabbitmqctl clear_vhost_limits -p qa_env
- list_vhost_limits [-p vhost] [--global]
- Displays configured virtual host limits.
- --global
- Show limits for all vhosts. Suppresses the -p parameter.
Server Status
The server status queries interrogate the server and return a list of results with tab-delimited columns. Some queries ( list_queues, list_exchanges, list_bindings and list_consumers) accept an optional vhost parameter. This parameter, if present, must be specified immediately after the query.
The list_queues, list_exchanges and list_bindings commands accept an optional virtual host parameter for which to display results. The default value is “/”.
- list_queues [-p vhost] [--offline | --online | --local] [queueinfoitem ...]
- Returns queue details. Queue details of the “/” virtual host are returned if the -p flag is absent. The -p flag can be used to override this default.
- --offline
- List only those durable queues that are not currently available (more specifically, their master node isn't).
- --online
- List queues that are currently available (their master node is).
- --local
- List only those queues whose master process is located on the current node.
- name
- The name of the queue with non-ASCII characters escaped as in C.
- durable
- Whether or not the queue survives server restarts.
- auto_delete
- Whether the queue will be deleted automatically when no longer used.
- arguments
- Queue arguments.
- policy
- Policy name applying to the queue.
- pid
- Id of the Erlang process associated with the queue.
- owner_pid
- Id of the Erlang process representing the connection which is the exclusive owner of the queue. Empty if the queue is non-exclusive.
- exclusive
- True if queue is exclusive (i.e. has owner_pid), false otherwise.
- exclusive_consumer_pid
- Id of the Erlang process representing the channel of the exclusive consumer subscribed to this queue. Empty if there is no exclusive consumer.
- exclusive_consumer_tag
- Consumer tag of the exclusive consumer subscribed to this queue. Empty if there is no exclusive consumer.
- messages_ready
- Number of messages ready to be delivered to clients.
- messages_unacknowledged
- Number of messages delivered to clients but not yet acknowledged.
- messages
- Sum of ready and unacknowledged messages (queue depth).
- messages_ready_ram
- Number of messages from messages_ready which are resident in ram.
- messages_unacknowledged_ram
- Number of messages from messages_unacknowledged which are resident in ram.
- messages_ram
- Total number of messages which are resident in ram.
- messages_persistent
- Total number of persistent messages in the queue (will always be 0 for transient queues).
- message_bytes
- Sum of the size of all message bodies in the queue. This does not include the message properties (including headers) or any overhead.
- message_bytes_ready
- Like message_bytes but counting only those messages ready to be delivered to clients.
- message_bytes_unacknowledged
- Like message_bytes but counting only those messages delivered to clients but not yet acknowledged.
- message_bytes_ram
- Like message_bytes but counting only those messages which are in RAM.
- message_bytes_persistent
- Like message_bytes but counting only those messages which are persistent.
- head_message_timestamp
- The timestamp property of the first message in the queue, if present. Timestamps of messages only appear when they are in the paged-in state.
- disk_reads
- Total number of times messages have been read from disk by this queue since it started.
- disk_writes
- Total number of times messages have been written to disk by this queue since it started.
- consumers
- Number of consumers.
- consumer_utilisation
- Fraction of the time (between 0.0 and 1.0) that the queue is able to immediately deliver messages to consumers. This can be less than 1.0 if consumers are limited by network congestion or prefetch count.
- memory
- Bytes of memory consumed by the Erlang process associated with the queue, including stack, heap and internal structures.
- slave_pids
- If the queue is mirrored, this gives the IDs of the current slaves.
- synchronised_slave_pids
- If the queue is mirrored, this gives the IDs of the current slaves which are synchronised with the master - i.e. those which could take over from the master without message loss.
- state
- The state of the queue. Normally “running”, but may be “{syncing, message_count}” if the queue is synchronising.
rabbitmqctl list_queues -p /myvhost messages consumers
- list_exchanges [-p vhost] [exchangeinfoitem ...]
- Returns exchange details. Exchange details of the “/” virtual host are returned if the -p flag is absent. The -p flag can be used to override this default.
- name
- The name of the exchange with non-ASCII characters escaped as in C.
- type
- The exchange type, such as:
- direct
- topic
- headers
- fanout
- durable
- Whether or not the exchange survives server restarts.
- auto_delete
- Whether the exchange will be deleted automatically when no longer used.
- internal
- Whether the exchange is internal, i.e. cannot be directly published to by a client.
- arguments
- Exchange arguments.
- policy
- Policy name for applying to the exchange.
rabbitmqctl list_exchanges -p /myvhost name type
- list_bindings [-p vhost] [bindinginfoitem ...]
- Returns binding details. By default the bindings for the “/” virtual host are returned. The -p flag can be used to override this default.
- source_name
- The name of the source of messages to which the binding is attached. With non-ASCII characters escaped as in C.
- source_kind
- The kind of the source of messages to which the binding is attached. Currently always exchange. With non-ASCII characters escaped as in C.
- destination_name
- The name of the destination of messages to which the binding is attached. With non-ASCII characters escaped as in C.
- destination_kind
- The kind of the destination of messages to which the binding is attached. With non-ASCII characters escaped as in C.
- routing_key
- The binding's routing key, with non-ASCII characters escaped as in C.
- arguments
- The binding's arguments.
rabbitmqctl list_bindings -p /myvhost exchange_name queue_name
- list_connections [connectioninfoitem ...]
- Returns TCP/IP connection statistics.
- pid
- Id of the Erlang process associated with the connection.
- name
- Readable name for the connection.
- port
- Server port.
- host
- Server hostname obtained via reverse DNS, or its IP address if reverse DNS failed or was disabled.
- peer_port
- Peer port.
- peer_host
- Peer hostname obtained via reverse DNS, or its IP address if reverse DNS failed or was not enabled.
- ssl
- Boolean indicating whether the connection is secured with SSL.
- ssl_protocol
- SSL protocol (e.g. “tlsv1”).
- ssl_key_exchange
- SSL key exchange algorithm (e.g. “rsa”).
- ssl_cipher
- SSL cipher algorithm (e.g. “aes_256_cbc”).
- ssl_hash
- SSL hash function (e.g. “sha”).
- peer_cert_subject
- The subject of the peer's SSL certificate, in RFC4514 form.
- peer_cert_issuer
- The issuer of the peer's SSL certificate, in RFC4514 form.
- peer_cert_validity
- The period for which the peer's SSL certificate is valid.
- state
- Connection state; one of:
- starting
- tuning
- opening
- running
- flow
- blocking
- blocked
- closing
- closed
- channels
- Number of channels using the connection.
- protocol
- Version of the AMQP protocol in use; currently one of:
- {0,9,1}
- {0,8,0}
- auth_mechanism
- SASL authentication mechanism used, such as “PLAIN”.
- user
- Username associated with the connection.
- vhost
- Virtual host name with non-ASCII characters escaped as in C.
- timeout
- Connection timeout / negotiated heartbeat interval, in seconds.
- frame_max
- Maximum frame size (bytes).
- channel_max
- Maximum number of channels on this connection.
- client_properties
- Informational properties transmitted by the client during connection establishment.
- recv_oct
- Octets received.
- recv_cnt
- Packets received.
- send_oct
- Octets send.
- send_cnt
- Packets sent.
- send_pend
- Send queue size.
- connected_at
- Date and time this connection was established, as timestamp.
rabbitmqctl list_connections send_pend port
- list_channels [channelinfoitem ...]
- Returns information on all current channels, the logical containers executing most AMQP commands. This includes channels that are part of ordinary AMQP connections, and channels created by various plug-ins and other extensions.
- pid
- Id of the Erlang process associated with the connection.
- connection
- Id of the Erlang process associated with the connection to which the channel belongs.
- name
- Readable name for the channel.
- number
- The number of the channel, which uniquely identifies it within a connection.
- user
- Username associated with the channel.
- vhost
- Virtual host in which the channel operates.
- transactional
- True if the channel is in transactional mode, false otherwise.
- confirm
- True if the channel is in confirm mode, false otherwise.
- consumer_count
- Number of logical AMQP consumers retrieving messages via the channel.
- messages_unacknowledged
- Number of messages delivered via this channel but not yet acknowledged.
- messages_uncommitted
- Number of messages received in an as yet uncommitted transaction.
- acks_uncommitted
- Number of acknowledgements received in an as yet uncommitted transaction.
- messages_unconfirmed
- Number of published messages not yet confirmed. On channels not in confirm mode, this remains 0.
- prefetch_count
- QoS prefetch limit for new consumers, 0 if unlimited.
- global_prefetch_count
- QoS prefetch limit for the entire channel, 0 if unlimited.
rabbitmqctl list_channels connection messages_unacknowledged
- list_consumers [-p vhost]
- Lists consumers, i.e. subscriptions to a queue´s message stream. Each line printed shows, separated by tab characters, the name of the queue subscribed to, the id of the channel process via which the subscription was created and is managed, the consumer tag which uniquely identifies the subscription within a channel, a boolean indicating whether acknowledgements are expected for messages delivered to this consumer, an integer indicating the prefetch limit (with 0 meaning “none”), and any arguments for this consumer.
- status
- Displays broker status information such as the running applications on the current Erlang node, RabbitMQ and Erlang versions, OS name, memory and file descriptor statistics. (See the cluster_status command to find out which nodes are clustered and running.)
rabbitmqctl status
- node_health_check
- Health check of the RabbitMQ node. Verifies the rabbit application is running, list_queues and list_channels return, and alarms are not set.
rabbitmqctl node_health_check -n rabbit@stringer
- environment
- Displays the name and value of each variable in the application environment for each running application.
- report
- Generate a server status report containing a concatenation of all server status information for support purposes. The output should be redirected to a file when accompanying a support request.
rabbitmqctl report > server_report.txt
- eval expr
- Evaluate an arbitrary Erlang expression.
rabbitmqctl eval “node().”
Miscellaneous
- close_connection connectionpid explanation
- connectionpid
- Id of the Erlang process associated with the connection to close.
- explanation
- Explanation string.
rabbitmqctl close_connection “<rabbit@tanto.4262.0>” “go away”
- close_all_connections [-p vhost] [--global] [--per-connection-delay delay] [--limit limit] explanation
- -p vhost
- The name of the virtual host for which connections should be closed. Ignored when --global is specified.
- --global
- If connections should be close for all vhosts. Overrides -p
- --per-connection-delay delay
- Time in milliseconds to wait after each connection closing.
- --limit limit
- Number of connection to close. Only works per vhost. Ignored when --global is specified.
- explanation
- Explanation string.
rabbitmqctl close_all_connections -p qa_env --limit 10 'Please close'
rabbitmqctl close_all_connections --global
- trace_on [-p vhost]
- vhost
- The name of the virtual host for which to start tracing.
- trace_off [-p vhost]
- vhost
- The name of the virtual host for which to stop tracing.
- set_vm_memory_high_watermark fraction
- fraction
- The new memory threshold fraction at which flow control is triggered, as a floating point number greater than or equal to 0.
- set_vm_memory_high_watermark absolute memory_limit
- memory_limit
- The new memory limit at which flow control is triggered, expressed in bytes as an integer number greater than or equal to 0 or as a string with memory units (e.g. 512M or 1G). Available units are:
- set_disk_free_limit disk_limit
- disk_limit
- Lower bound limit as an integer in bytes or a string with memory units (see vm_memory_high_watermark), e.g. 512M or 1G. Once free disk space reaches the limit, a disk alarm will be set.
- set_disk_free_limit mem_relative fraction
- fraction
- Limit relative to the total amount available RAM as a non-negative floating point number. Values lower than 1.0 can be dangerous and should be used carefully.
- encode value passphrase [--cipher cipher] [--hash hash] [--iterations iterations]
- value passphrase
- Value to encrypt and passphrase.
rabbitmqctl encode '<<"guest">>' mypassphrase
- --cipher cipher --hash hash --iterations iterations
- Options to specify the encryption settings. They can be used independently.
rabbitmqctl encode --cipher blowfish_cfb64 --hash sha256 --iterations 10000 '<<"guest">>' mypassphrase
- decode value passphrase [--cipher cipher] [--hash hash] [--iterations iterations]
- value passphrase
- Value to decrypt (as produced by the encode command) and passphrase.
rabbitmqctl decode '{encrypted, <<"...">>}' mypassphrase
- --cipher cipher --hash hash --iterations iterations
- Options to specify the decryption settings. They can be used independently.
rabbitmqctl decode --cipher blowfish_cfb64 --hash sha256 --iterations 10000 '{encrypted,<<"...">>} mypassphrase
- list_hashes
- Lists hash functions supported by encoding commands.
rabbitmqctl list_hashes
- list_ciphers
- Lists cipher suites supported by encoding commands.
rabbitmqctl list_ciphers
PLUGIN COMMANDS
RabbitMQ plugins can extend rabbitmqctl tool to add new commands when enabled. Currently available commands can be found in rabbitmqctl help output. Following commands are added by RabbitMQ plugins, available in default distribution:
Shovel plugin
- shovel_status
- Prints a list of configured shovels
- delete_shovel [-p vhost] name
- Instructs the RabbitMQ node to delete the configured shovel by name.
Federation plugin
- federation_status [--only-down]
- Prints a list of federation links.
- --only-down
- Only list federation links which are not running.
- restart_federation_link link_id
- Instructs the RabbitMQ node to restart the federation link with specified link_id.
AMQP-1.0 plugin
- list_amqp10_connections [amqp10_connectioninfoitem ...]
- Similar to the list_connections command, but returns fields which make sense for AMQP-1.0 connections. amqp10_connectioninfoitem parameter is used to indicate which connection information items to include in the results. The column order in the results will match the order of the parameters. amqp10_connectioninfoitem can take any value from the list that follows:
- pid
- Id of the Erlang process associated with the connection.
- auth_mechanism
- SASL authentication mechanism used, such as “PLAIN”.
- host
- Server hostname obtained via reverse DNS, or its IP address if reverse DNS failed or was disabled.
- frame_max
- Maximum frame size (bytes).
- timeout
- Connection timeout / negotiated heartbeat interval, in seconds.
- user
- Username associated with the connection.
- state
- Connection state; one of:
- starting
- waiting_amqp0100
- securing
- running
- blocking
- blocked
- closing
- closed
- recv_oct
- Octets received.
- recv_cnt
- Packets received.
- send_oct
- Octets send.
- send_cnt
- Packets sent.
- ssl
- Boolean indicating whether the connection is secured with SSL.
- ssl_protocol
- SSL protocol (e.g. “tlsv1”).
- ssl_key_exchange
- SSL key exchange algorithm (e.g. “rsa”).
- ssl_cipher
- SSL cipher algorithm (e.g. “aes_256_cbc”).
- ssl_hash
- SSL hash function (e.g. “sha”).
- peer_cert_subject
- The subject of the peer's SSL certificate, in RFC4514 form.
- peer_cert_issuer
- The issuer of the peer's SSL certificate, in RFC4514 form.
- peer_cert_validity
- The period for which the peer's SSL certificate is valid.
- node
- The node name of the RabbitMQ node to which connection is established.
MQTT plugin
- list_mqtt_connections [mqtt_connectioninfoitem]
- Similar to the list_connections command, but returns fields which make sense for MQTT connections. mqtt_connectioninfoitem parameter is used to indicate which connection information items to include in the results. The column order in the results will match the order of the parameters. mqtt_connectioninfoitem can take any value from the list that follows:
- host
- Server hostname obtained via reverse DNS, or its IP address if reverse DNS failed or was disabled.
- port
- Server port.
- peer_host
- Peer hostname obtained via reverse DNS, or its IP address if reverse DNS failed or was not enabled.
- peer_port
- Peer port.
- protocol
- MQTT protocol version, which can be on of the following:
- {'MQTT', N/A}
- {'MQTT', 3.1.0}
- {'MQTT', 3.1.1}
- channels
- Number of channels using the connection.
- channel_max
- Maximum number of channels on this connection.
- frame_max
- Maximum frame size (bytes).
- client_properties
- Informational properties transmitted by the client during connection establishment.
- ssl
- Boolean indicating whether the connection is secured with SSL.
- ssl_protocol
- SSL protocol (e.g. “tlsv1”).
- ssl_key_exchange
- SSL key exchange algorithm (e.g. “rsa”).
- ssl_cipher
- SSL cipher algorithm (e.g. “aes_256_cbc”).
- ssl_hash
- SSL hash function (e.g. “sha”).
- conn_name
- Readable name for the connection.
- connection_state
- Connection state; one of:
- starting
- running
- blocked
- connection
- Id of the Erlang process associated with the internal amqp direct connection.
- consumer_tags
- A tuple of consumer tags for QOS0 and QOS1.
- message_id
- The last Packet ID sent in a control message.
- client_id
- MQTT client identifier for the connection.
- clean_sess
- MQTT clean session flag.
- will_msg
- MQTT Will message sent in CONNECT frame.
- exchange
- Exchange to route MQTT messages configured in rabbitmq_mqtt application environment.
- ssl_login_name
- SSL peer cert auth name
- retainer_pid
- Id of the Erlang process associated with retain storage for the connection.
- user
- Username associated with the connection.
- vhost
- Virtual host name with non-ASCII characters escaped as in C.
STOMP plugin
- list_stomp_connections [stomp_connectioninfoitem]
- Similar to the list_connections command, but returns fields which make sense for STOMP connections. stomp_connectioninfoitem parameter is used to indicate which connection information items to include in the results. The column order in the results will match the order of the parameters. stomp_connectioninfoitem can take any value from the list that follows:
- conn_name
- Readable name for the connection.
- connection
- Id of the Erlang process associated with the internal amqp direct connection.
- connection_state
- Connection state; one of:
- running
- blocking
- blocked
- session_id
- STOMP protocol session identifier
- channel
- AMQP channel associated with the connection
- version
- Negotiated STOMP protocol version for the connection.
- implicit_connect
- Indicates if the connection was established using implicit connect (without CONNECT frame)
- auth_login
- Effective username for the connection.
- auth_mechanism
- STOMP authorization mechanism. Can be one of:
- config
- ssl
- stomp_headers
- port
- Server port.
- host
- Server hostname obtained via reverse DNS, or its IP address if reverse DNS failed or was not enabled.
- peer_port
- Peer port.
- peer_host
- Peer hostname obtained via reverse DNS, or its IP address if reverse DNS failed or was not enabled.
- protocol
- STOMP protocol version, which can be on of the following:
- {'STOMP', 0}
- {'STOMP', 1}
- {'STOMP', 2}
- channels
- Number of channels using the connection.
- channel_max
- Maximum number of channels on this connection.
- frame_max
- Maximum frame size (bytes).
- client_properties
- Informational properties transmitted by the client during connection
- ssl
- Boolean indicating whether the connection is secured with SSL.
- ssl_protocol
- SSL protocol (e.g. “tlsv1”).
- ssl_key_exchange
- SSL key exchange algorithm (e.g. “rsa”).
- ssl_cipher
- SSL cipher algorithm (e.g. “aes_256_cbc”).
- ssl_hash
- SSL hash function (e.g. “sha”).
Management agent plugin
- reset_stats_db [--all]
- Reset management stats database for the RabbitMQ node.
- --all
- Reset stats database for all nodes in the cluster.
SEE ALSO
rabbitmq-env.conf(5), rabbitmq-echopid(8), rabbitmq-plugins(8), rabbitmq-server(8), rabbitmq-service(8)
AUTHOR
The RabbitMQ Team <info@rabbitmq.com>
【参考】
rabbitmq 启动报错 - 粽先生 - 博客园 https://www.cnblogs.com/straycats/p/7719933.html
【测试代码】
Asynchronous publisher example — pika 0.12.0 documentation https://pika.readthedocs.io/en/stable/examples/asynchronous_publisher_example.html
Why does the queue memory grow and shrink when publishing/consuming?
http://www.rabbitmq.com/memory-use.html#queue-memory-usage http://www.rabbitmq.com/memory-use.html#queue-memory-usage
AMQP,即Advanced Message Queuing Protocol,一个提供统一消息服务的应用层标准高级消息队列协议,是应用层协议的一个开放标准,为面向消息的中间件设计。基于此协议的客户端与消息中间件可传递消息,并不受客户端/中间件不同产品,不同的开发语言等条件的限制。Erlang中的实现有 RabbitMQ等。
- 中文名
- 高级消息队列协议
- 外文名
- Advanced Message Queuing Protocol
- 属 性
- 应用层标准协议
- 应用领域
- 计算机
-
简介
编辑AMQP协议第1章 概述1.3. 摘要1.3.1. 什么是AMQP高级消息队列协议使得遵从该规范的客户端应用和消息中间件服务器的全功能互操作成为可能。1.3.2. 为什么要用AMQP我们的目标是实现一种在全行业广泛使用的标准消息中间件技术,以便降低企业和系统集成的开销,并且向大众提供工业级的集成服务。我们的宗旨是通过AMQP,让消息中间件的能力最终被网络本身所具有,并且通过消息中间件的广泛使用发展出一系列有用的应用程序。1.3.3. AMQP的范围为了完全实现消息中间件的互操作性,需要充分定义网络协议和消息代理服务的功能语义。因此,AMQP定义网络协议和代理服务如下:一套确定的消息交换功能,也就是“高级消息交换协议模型”。AMQP模型包括一套用于路由和存储消息的功能模块,以及一套在这些模块之间交换消息的规则。一个网络线级协议(数据传输格式),客户端应用可以通过这个协议与消息代理和它实现的AMQP模型进行交互通信。可以只实现AMQP协议规范中的的部分语义,但是我们相信明确的描述这些语义有助于理解这个协议。相关协议
编辑1.3.4.1. AMQP模型我们需要明确的定义服务器的语义,因为所有服务器实现都应该保持这些语义的一致性,否则就无法进行互操作。因此AMQP模型描述了一套模块化的组件以及这些组件之间进行连接的标准规则。在服务器中,三个主要功能模块连接成一个处理链完成预期的功能:“exchange”接收发布应用程序发送的消息,并根据一定的规则将这些消息路由到“消息队列”。“message queue”存储消息,直到这些消息被消费者安全处理完为止。“binding”定义了exchange和message queue之间的关联,提供路由规则。使用这个模型我们可以很容易的模拟出存储转发队列和主题订阅这些典型的消息中间件概念。一个AMQP服务器类似于邮件服务器,exchange类似于消息传输代理(email里的概念),message queue类似于邮箱。Binding定义了每一个传输代理中的消息路由表,发布者将消息发给特定的传输代理,然后传输代理将这些消息路由到邮箱中,消费者从这些邮箱中取出消息。在以前的中间件系统的应用场景中,发布者直接将消息发送给邮箱或者邮件列表。区别就在于用户可以控制message queue与exchage的连接规则,这可以做很多有趣的事情,比如定义一条规则:“将所有包含这样这样的消息头的消息都复制一份再发送到消息队列中”。AMQP模型有以下目标:支持金融服务领域的语义要求。支持金融服务领域所要求的性能要求。能够很方便的扩展新的消息路由和队列。通过AMQP协议(AMQP和AMQP Protocol的是整体和部分的关系),服务器应用可以通过编程的方式来实现具体的功能语义。简单而灵活。1.3.4.2. AMQP协议AMQP协议是一个二进制协议,拥有一些现代特点:多信道、协商式、异步、安全、跨平台、中立、高效。AMQP通常被划分为三层:模型层定义了一套命令(按功能分类),客户端应用可以利用这些命令来实现它的业务功能。会话层负责将命令从客户端应用传递给服务器,再将服务器的应答传递给客户端应用,会话层为这个传递过程提供可靠性、同步机制和错误处理。传输层提供帧处理、信道复用、错误检测和数据表示。实现者可以将传输层替换成任意传输协议,只要不改变AMQP协议中与客户端应用程序相关的功能。实现者还可以使用其他高层协议中的会话层。AMQP模型的设计由以下几个需求所驱动:保证遵从AMQP规范的服务器实现之间能够进行互操作。为服务质量提供显示控制。支持所有消息中间件的功能:消息交换、文件传输、流传输、远程进程调用等。兼容已有的消息API规范(比如Sun公司的JMS规范)。形成一致和明确的命名。通过AMQP协议可以完整的配置服务器线路(TODO:server wiring是啥意思?答:服务器连接)。使用命令符号可以很容易的映射成应用级别的API。明确定义每一个操作只做一件事情。AMQP传输层的设计由以下几个主要的需求所驱动,这些需求不分先后次序:使用能够快速打包解包的二进制编码来保证数据的紧凑性。能够处理任意大小的消息。允许零拷贝数据传输(比如远程DMA)。一个连接支持多个会话。保证会话能够从网络错误、服务器失效中恢复。为了长期存在,没有隐含的内置限制(TODO:To be long-lived,with no significant in-built limitations)。异步传输消息。能够很容易的处理新的和变化的需求。高版本的AMQP规范能够兼容低版本的规范。使用强断言模型来保证应用程序的可修复性。保持编程语言的中立性。适宜使用代码生成工具生成协议处理模块。功能范围
编辑我们支持各种消息交换的体系结构:存储转发(多个消息发送者,单个消息接收者)。分布式事务(多个消息发送者,多个消息接收者)。发布订阅(多个消息发送者,多个消息接收者)。基于内容的路由(多个消息发送者,多个消息接收者)。文件传输队列(多个消息发送者,多个消息接收者)。点对点连接(单个消息发送者,单个消息接收者)。文档结构
编辑本文档分成两个部分:“概念”部分将对AMQP的概念做一个简单的介绍,描述AMQP怎么工作,以及AMQP的用途。“标准”部分将对AMQP的模型层、会话层的每个组成部分做精确的定义,还将定义AMQP在网络上传输的二进制消息结构。当我们讨论遵从AMQP规范的服务器的具体行为时,我们使用术语“服务器”来表示这些服务器。当我们讨论遵从AMQP规范的客户端应用的具体行为时,我们使用术语“客户端”来表示这些客户端应用。我们使用“端点”来表示“服务器或者客户端”。除非另有说明,所有数字都是十进制的。协议中的常量都用大写字母的名字来表示。AMQP的实现如果需要在代码或者文档中定义和使用这些常量,必须用这些名字来表示。属性名、命令或者控制参数,以及帧字段都用小写字母的名字来表示。AMQP的实现必须在代码或者文档中与之保持一致。1.5. 约定1.5.1. 定义1.5.2. 版本号AMQP版本用两个版本号表示——主版本号和次版本号。我们约定版本由主版本号后面加小数点再加上次版本号组成(比如1-3表示主版本号为1,次版本号为3)。主版本号和次版本号可以用0到255之内的所有值。主版本号保持不变,次版本号递增。当AMQP工作组提升主版本号时,次版本号将被设置为0。因此,有可能出现这样的版本序列:1-2,1-3,1-4,2-0,2-1……一旦本协议发布之后(主版本号大于1),应尽量防止次版本号递增到9。不过在发布之前(版本0-x),由于会对本协议进行频繁的修订,可以不遵守这条约定。一旦本协议发布之后(主版本号大于1),同一个主版本不同次版本的实现必须向后兼容。而在发布之前,这些次版本的实现不需要兼容。大于或者等于99的主版本号用于测试和开发目的。技术术语
编辑AMQP模型(AMQP Model):一个由关键实体和语义表示的逻辑框架,遵从AMQP规范的服务器必须提供这些实体和语义。为了实现本规范中定义的语义,客户端可以发送命令来控制AMQP服务器。连接(Connection):一个网络连接,比如TCP/IP套接字连接。会话(Session):端点之间的命名对话。在一个会话上下文中,保证“恰好传递一次”。信道(Channel):多路复用连接中的一条独立的双向数据流通道。为会话提供物理传输介质。客户端(Client):AMQP连接或者会话的发起者。AMQP是非对称的,客户端生产和消费消息,服务器存储和路由这些消息。服务器(Server):接受客户端连接,实现AMQP消息队列和路由功能的进程。也称为“消息代理”。端点(Peer):AMQP对话的任意一方。一个AMQP连接包括两个端点(一个是客户端,一个是服务器)。搭档(Partner):当描述两个端点之间的交互过程时,使用术语“搭档”来表示“另一个”端点的简记法。比如我们定义端点A和端点B,当它们进行通信时,端点B是端点A的搭档,端点A是端点B的搭档。片段集(Assembly):段的有序集合,形成一个逻辑工作单元。段(Segment):帧的有序集合,形成片段集中一个完整子单元。帧(Frame):AMQP传输的一个原子单元。一个帧是一个段中的任意分片。控制(Control):单向指令,AMQP规范假设这些指令的传输是不可靠的。命令(Command):需要确认的指令,AMQP规范规定这些指令的传输是可靠的。异常(Exception):在执行一个或者多个命令时可能发生的错误状态。类(Class):一批用来描述某种特定功能的AMQP命令或者控制。消息头(Header):描述消息数据属性的一种特殊段。消息体(Body):包含应用程序数据的一种特殊段。消息体段对于服务器来说完全透明——服务器不能查看或者修改消息体。消息内容(Content):包含在消息体段中的的消息数据。交换器(Exchange):服务器中的实体,用来接收生产者发送的消息并将这些消息路由给服务器中的队列。交换器类型(Exchange Type):基于不同路由语义的交换器类。消息队列(Message Queue):一个命名实体,用来保存消息直到发送给消费者。绑定器(Binding):消息队列和交换器之间的关联。绑定器关键字(Binding Key):绑定的名称。一些交换器类型可能使用这个名称作为定义绑定器路由行为的模式。路由关键字(Routing Key):一个消息头,交换器可以用这个消息头决定如何路由某条消息。持久存储(Durable):一种服务器资源,当服务器重启时,保存的消息数据不会丢失。临时存储(Transient):一种服务器资源,当服务器重启时,保存的消息数据会丢失。持久化(Persistent):服务器将消息保存在可靠磁盘存储中,当服务器重启时,消息不会丢失。非持久化(Non-Persistent):服务器将消息保存在内存中,当服务器重启时,消息可能丢失。消费者(Consumer):一个从消息队列中请求消息的客户端应用程序。生产者(Producer):一个向交换器发布消息的客户端应用程序。虚拟主机(Virtual Host):一批交换器、消息队列和相关对象。虚拟主机是共享相同的身份认证和加密环境的独立服务器域。客户端应用程序在登录到服务器之后,可以选择一个虚拟主机。下面这些术语在AMQP规范的上下文中没有特别的意义:主题:通常指发布消息;AMQP规范用一种或多种交换器来实现主题。服务:通常等同于服务器。AMQP规范使用“服务器”这个术语来兼容IETF的标准术语,并且明确了协议中每个部分的角色(两方也可能是AMQP服务)。消息代理:等同于服务器。AMQP规范使用术语“客户端”和“服务器”来兼容IETF的标准术语。
RabbitMQ libraries
RabbitMQ speaks multiple protocols. This tutorial uses AMQP 0-9-1, which is an open, general-purpose protocol for messaging. There are a number of clients for RabbitMQ in many different languages. In this tutorial series we're going to use Pika 1.0.0, which is the Python client recommended by the RabbitMQ team.
In RabbitMQ a message can never be sent directly to the queue, it always needs to go through an exchange. But let's not get dragged down by the details ‒ you can read more about exchanges in the third part of this tutorial. All we need to know now is how to use a default exchange identified by an empty string. This exchange is special ‒ it allows us to specify exactly to which queue the message should go. The queue name needs to be specified in the routing_key parameter:
channel.basic_publish(exchange='',
routing_key='hello',
body='Hello World!')
print(" [x] Sent 'Hello World!'")
Before exiting the program we need to make sure the network buffers were flushed and our message was actually delivered to RabbitMQ. We can do it by gently closing the connection.
connection.close()
消息不能直接发送至队列,需要通过exchange。
初始默认的exchange "" Exchange: (AMQP default)
publish/subscrib 发布订阅
同一个消息多个消费者场景
https://www.rabbitmq.com/tutorials/tutorial-three-python.html
What This Tutorial Focuses On
In the previous tutorial we created a work queue. The assumption behind a work queue is that each task is delivered to exactly one worker. In this part we'll do something completely different -- we'll deliver a message to multiple consumers. This pattern is known as "publish/subscribe".
To illustrate the pattern, we're going to build a simple logging system. It will consist of two programs -- the first will emit log messages and the second will receive and print them.
In our logging system every running copy of the receiver program will get the messages. That way we'll be able to run one receiver and direct the logs to disk; and at the same time we'll be able to run another receiver and see the logs on the screen.
Essentially, published log messages are going to be broadcast to all the receivers.
发布者不知道队列queue ,只知道交易所 exchange,exchange决定发至哪个队列
The core idea in the messaging model in RabbitMQ is that the producer never sends any messages directly to a queue. Actually, quite often the producer doesn't even know if a message will be delivered to any queue at all.
Instead, the producer can only send messages to an exchange. An exchange is a very simple thing. On one side it receives messages from producers and the other side it pushes them to queues. The exchange must know exactly what to do with a message it receives. Should it be appended to a particular queue? Should it be appended to many queues? Or should it get discarded. The rules for that are defined by the exchange type.
There are a few exchange types available: direct, topic, headers and fanout. We'll focus on the last one -- the fanout. Let's create an exchange of that type, and call it logs:
channel.exchange_declare(exchange='logs',
exchange_type='fanout')
The fanout exchange is very simple. As you can probably guess from the name, it just broadcasts all the messages it receives to all the queues it knows. And that's exactly what we need for our logger.
数据多写 交易所类型
exchange_type='fanout'
注意
Add binding from this exchange
交易所exchange可以绑定交易所或队列queue
创建顺序
NOT_FOUND - no queue 'queue_19_ehr_analysis_log' in vhost '/'
Close
并行/发 创建 exchange queue
之后做绑定
Exchange: exchange_19_ehr_analysis_log
This exchange
⇓
To | Routing key | Arguments | |
---|---|---|---|
queue_19_ehr_analysis_log | routing_key_19_ehr_analysis_log |
'''
exchange_19_ehr_analysis_log
Details
Type direct
Parameters
durable: true
Policy
注意双写/多写Type可以改为 fanout
queue_19_ehr_analysis_log 配置
Parameters
durable: true
Policy
Exclusive owner None
路由关系
From Routing key Arguments
(Default exchange binding)
exchange_19_ehr_analysis_log
routing_key_19_ehr_analysis_log
⇓
This queue
'''
注意双写/多写Type可以改为 fanout
requeue yes 不从队列删除