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dido:public:ra:xapend:xapend.f_qos:reliability [2021/06/22 00:23]
char
dido:public:ra:xapend:xapend.f_qos:reliability [2021/10/03 15:31] (current)
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 ====== F.14 Reliability ====== ====== F.14 Reliability ======
-[[dido:​public:​ra:​xapend:​xapend.f_qos| Return to DDS Quality of Service ]]+[[dido:​public:​ra:​xapend:​xapend.f_qos:start| Return to DDS Quality of Service ]]
  
-The RELIABILITY policy indicates the level of reliability requested by a ''​DataReader''​ or offered by a ''​DataWriter''​. These levels are ordered, BEST_EFFORT being lower than RELIABLE. A DataWriter offering a level is implicitly offering all levels below.+The RELIABILITY ​[[dido:​public:​ra:​xapend:​xapend.a_glossary:​p:​policy|policy]] ​indicates the level of reliability requested by a ''​DataReader''​ or offered by a ''​DataWriter''​. These levels are ordered, BEST_EFFORT being lower than RELIABLE. A DataWriter offering a level is implicitly offering all levels below.
  
 The setting of this policy has a dependency on the setting of the RESOURCE_LIMITS policy. In case the RELIABILITY ''​kind''​ is set to RELIABLE the ''​write''​ operation on the DataWriter may block if the modification would cause data to be lost or else cause one of the limits in specified in the RESOURCE_LIMITS to be exceeded. Under these circumstances,​ the RELIABILITY max_blocking_time configures the maximum duration the ''​write''​ operation may block. The setting of this policy has a dependency on the setting of the RESOURCE_LIMITS policy. In case the RELIABILITY ''​kind''​ is set to RELIABLE the ''​write''​ operation on the DataWriter may block if the modification would cause data to be lost or else cause one of the limits in specified in the RESOURCE_LIMITS to be exceeded. Under these circumstances,​ the RELIABILITY max_blocking_time configures the maximum duration the ''​write''​ operation may block.
  
-If the RELIABILITY ''​kind''​ is set to RELIABLE, data-samples originating from a single ''​DataWriter''​ cannot be made available to the ''​DataReader''​ if there are previous data-samples that have not been received yet due to a communication error. In other words, the service will repair the error and re-transmit data-samples as needed in order to re-construct a correct snapshot of the ''​DataWriter''​ history before it is accessible by the ''​DataReader''​.+If the RELIABILITY ''​kind''​ is set to RELIABLE, data-samples originating from a single ''​DataWriter''​ cannot be made available to the ''​DataReader''​ if there are previous data-samples that have not been received yet due to a communication error. In other words, the service will repair the error and re-transmit data-samples as needed in order to re-construct a correct ​[[dido:​public:​ra:​xapend:​xapend.a_glossary:​s:​snapshot|snapshot]] ​of the ''​DataWriter''​ history before it is accessible by the ''​DataReader''​.
  
 If the RELIABILITY ''​kind''​ is set to BEST_EFFORT,​ the service will not re-transmit missing data-samples. However for datasamples originating from any one ''​DataWriter''​ the service will ensure they are stored in the ''​DataReader''​ history in the same order they originated in the ''​DataWriter''​. In other words, the ''​DataReader''​ may miss some data-samples but it will never see the value of a data-object change from a newer value to an order value. If the RELIABILITY ''​kind''​ is set to BEST_EFFORT,​ the service will not re-transmit missing data-samples. However for datasamples originating from any one ''​DataWriter''​ the service will ensure they are stored in the ''​DataReader''​ history in the same order they originated in the ''​DataWriter''​. In other words, the ''​DataReader''​ may miss some data-samples but it will never see the value of a data-object change from a newer value to an order value.
dido/public/ra/xapend/xapend.f_qos/reliability.1624335801.txt.gz · Last modified: 2021/06/22 00:23 by char