You can set the properties directly in the topics.conf or queues.conf file or by means of the setprop topic or setprop queue command in the EMS Administrator Tool. 1) Failsafe The failsafe property determines whether the server writes persistent messages to disk synchronously or asynchronously. Ø When failsafe is not set, messages are written to the file on disk in asynchronous mode to obtain maximum performance. In this mode, the data may remain in system buffers for a short time before it is written to disk and it is possible that, in case of software or hardware failure, some data could be lost without the possibility of recovery Ø In failsafe mode, all data for that queue or topic are written into external storage in synchronous mode. In synchronous mode, a write operation is not complete until the data is physically recorded on the external device The failsafe property ensures that no messages are ever lost in case of server
JMS queue Sender: – It simply sends the message to specified queue and does not wait for any response. JMS Queue Requestor: – It send the message to specified queue and waits for the response from JMS client like SOAP request reply activity. The flow will not proceed until it gets the response or the request gets timed out. This activity uses temporary queues to ensure that reply messages are received only by the process that sent the request. Input tab :- Reply to Queue :- It is the name of the queue in which this activity is awaiting for the reply . If leave blank,then a temporary queue will be automatically created by Tibco as shown below in the screenshot. (Run show queues command in the Tibco EMS admin .All the queues starting with * is either temporary or dynamic queues) We can also give the name of Temporary queue. Request Timeout :- If the response come within the
What are the messaging models does EMS support? Point-to-Point (Queue) b. Publish and Subscribe (Topic) c. Multicast (Topic) There are two major models for messaging supported by JMS: queues and topics. Queues are based on a point-to-point messaging model. Topics make use of the new publish-and-subscribe messaging model. Regardless whether queues or topics are used, the messages are not sent directly peer-to-peer. Messages are forwarded to a JMS infrastructure that is composed of one or more JMS servers. The servers are responsible for providing the quality-of-services to JMS and responsible for implementing all the components not addressed by JMS Specification. When determining when to use queues versus topics consider the two fundamental messaging mechanisms. The first is point-to-point messaging, in which a message is sent by one publisher (sender) and received by one subscriber (receiver). The second is publish-subscribe messaging, in which a message is sent by one or more publishers and received by one or more subscribers. The
TESTED AT RUNTIME.
Very often we come across this kind of an error :- Most probably if your EMS is running as a 32bit Binary and your message size is exceeding 1.6 – 2 GB in size EMS For 32 bit has a size limitation of 2 GB When you are using Filesystem as a datastore, and when you come across such a trace 2007-07-24 10:46:38 Recovering state, please wait. 2007-07-24 10:48:47 SEVERE ERROR: Failed writing message to ‘datastore/meta.db’: No memory for operation. 2007-07-24 10:48:50 SEVERE ERROR: No memory processing purge record. 2007-07-24 10:48:52 FATAL: Exception in startup, exiting. 434692644 Jul 24 11:16 meta.db 29220 Jul 24 08:54 sync-msgs.db 5805854244 Jul 24 08:37 async-msgs.db Don’t Panic, Its a very Generic issue Just follow these checklists Size of your message Ensure you are using 64 bit EMS binary Set max_msg_memory= <XX>GB in your tibemsd.conf, where XX indicated the Memory in GB you wanna assign. Set msg_swapping=enabled. max_msg_memory max_msg_memory = size [KB|MB|GB] Maximum memory the
Multicast Messaging: Multicast is a messaging model that allows the EMS server to send messages to multiple consumers simultaneously by broadcasting them over an existing network. Overview: Multicast is a messaging model that broadcasts messages to many consumers at once, as opposed to sending copies of a message to each subscribing consumer individually. The server sends multicast messages over a multicast channel. Each multicast-enabled topic is associated with a channel. The channel determines the multicast port and multicast group address to which the server sends messages. The multicast message is received by a multicast daemon running on the same computer with the message consumer. When an EMS client subscribes to a multicast-enabled topic, it automatically connects to the multicast daemon. The multicast daemon begins listening on the channel associated with that topic, receives any broadcast messages, and delivers them to subscribed clients. When to use Multicast: Because multicast reduces the number of operations performed by the server and reduces the amount of bandwidth
The error message “Slow clock tick xx, delayed messaging and timeouts may occur” was added in EMS 5.1.4 for defect #1-A35PT9 -The server can disconnect clients or other servers if it gets very busy such that it does not service incoming heartbeats within the server_timeout_client_connection or server_timeout_server_connection period. The number xx indicates the delay when the timer thread is behind the current time, indicating that the EMS server has become busy. The value of xx is the time difference in seconds. This is an Informational message and is not detrimental to EMS, rather it is an indication that the EMS server is busy and delayed messaging and timeouts may occur.
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ft_active ft_active = URL Specifies the URL of the active server. If this server can connect to the active server, it will act as a backup server. If this server cannot connect to the active server, it will become the active server. ft_heartbeat ft_heartbeat = seconds Specifies the interval (in seconds) the active server is to send a heartbeat signal to the backup server to indicate that it is still operating. Default is 3 seconds. ft_activation ft_activation = seconds Activation interval (maximum length of time between heartbeat signals) which indicates that active server has failed. Set in seconds: default is 10. This interval should be set to at least twice the heartbeat interval. For example: ft_activation = 60 Note: The ft_activation parameter is only used by the backup server after a fault-tolerant switchover. The active server uses the server_timeout_server_connection to detect a failed server. ft_reconnect_timeout ft_reconnect_timeout = seconds The amount of time (in seconds)