ddsf:public:guidebook:06_append:02_quality_of_service:destination_order
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ddsf:public:guidebook:06_append:02_quality_of_service:destination_order [2020/06/05 02:04] admin ↷ Links adapted because of a move operation |
ddsf:public:guidebook:06_append:02_quality_of_service:destination_order [2021/07/14 15:55] (current) murphy ↷ Links adapted because of a move operation |
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| ====== DESTINATION_ORDER QoS Parameter ====== | ====== DESTINATION_ORDER QoS Parameter ====== | ||
| - | [[ddsf:private:cookbook:04_append:02_quality_of_service|return to the Quality of Service (QoS) Parameters ]] | + | [[ddsf:public:guidebook:06_append:02_quality_of_service:start|return to the Quality of Service (QoS) Parameters ]] |
| - | The DESTINATION_ORDER policy controls how each subscriber resolves the final value of a data instance that is written by multiple ''DataWriter'' | + | The DESTINATION_ORDER policy controls how each [[ddsf:public:guidebook:06_append:glossary:s:subscriber|subscriber]] resolves the final value of a data [[ddsf:public:guidebook:06_append:glossary:i:instance|instance]] that is written by multiple ''DataWriter'' |
| - | objects (which may be associated with different ''Publisher'' objects) running on different nodes. | + | objects (which may be associated with different ''[[ddsf:public:guidebook:06_append:glossary:p:publisher|Publisher]]'' objects) running on different nodes. |
| - | The setting BY_RECEPTION_TIMESTAMP indicates that, assuming the OWNERSHIP policy allows it, the latest received | + | The setting BY_RECEPTION_TIMESTAMP indicates that, assuming the [[ddsf:public:guidebook:06_append:glossary:o:ownership_qos|OWNERSHIP]] policy allows it, the latest received |
| value for the instance should be the one whose value is kept. This is the default value. | value for the instance should be the one whose value is kept. This is the default value. | ||
| The setting BY_SOURCE_TIMESTAMP indicates that, assuming the OWNERSHIP policy allows it, a timestamp placed at | The setting BY_SOURCE_TIMESTAMP indicates that, assuming the OWNERSHIP policy allows it, a timestamp placed at | ||
| - | the source should be used. This is the only setting that, in the case of concurrent same-strength ''DataWriter'' objects updating the same instance, ensures all subscribers will end up with the same final value for the instance. The mechanism to set the source timestamp is middleware dependent. | + | the source should be used. This is the only setting that, in the case of concurrent same-[[ddsf:public:guidebook:06_append:02_quality_of_service:ownership_strength|strength]] ''DataWriter'' objects updating the same instance, ensures all subscribers will end up with the same final value for the instance. The mechanism to set the source timestamp is [[ddsf:public:guidebook:06_append:glossary:m:midware|middleware]] dependent. |
| The value offered is considered compatible with the value requested if and only if the inequality ''offered kind >= requested kind'' evaluates to ''TRUE''. For the purposes of this inequality, the values of DESTINATION_ORDER ''kind'' are considered ordered such that ''BY_RECEPTION_TIMESTAMP < BY_SOURCE_TIMESTAMP''. | The value offered is considered compatible with the value requested if and only if the inequality ''offered kind >= requested kind'' evaluates to ''TRUE''. For the purposes of this inequality, the values of DESTINATION_ORDER ''kind'' are considered ordered such that ''BY_RECEPTION_TIMESTAMP < BY_SOURCE_TIMESTAMP''. | ||
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| Source: [[https://www.omg.org/spec/DDS/1.4/PDF | DDS 1.4 Spec]] | Source: [[https://www.omg.org/spec/DDS/1.4/PDF | DDS 1.4 Spec]] | ||
| + | /**=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- | ||
| + | /* To add a discussion page to this page, comment out the line that says | ||
| + | ~~DISCUSSION:off~~ | ||
| + | */ | ||
| + | ~~DISCUSSION:on|Outstanding Issues~~ | ||
| + | ~~DISCUSSION:off~~ | ||
ddsf/public/guidebook/06_append/02_quality_of_service/destination_order.1591337056.txt.gz · Last modified: 2020/06/05 02:04 by admin
