红帽全球峰会228.9. 启用持久跟踪
要启用此功能，在端点 URI 中至少设置以下选项：
-
persistentTailTracking选项为true -
persistentId选项针对这个消费者的唯一标识符，以便可以在许多用户间重复使用相同的集合
另外，您还可以将 tailTrackDb、tailTrackCollection 和 tailTrackField 选项设置为保存运行时信息的自定义。有关每个选项的描述，请参考本页顶部的端点选项表。
例如，以下路由会使用 "flights.cancellations" 容量收集，使用 "departureTime" 作为 increasing 字段，默认的重新生成光标延迟为 1000ms，并打开持久跟踪，并保留在 "flights.camelTailTracking" 的"cancellationsTracker" id 下。 在 "lastTrackingValue" 字段中存储最后处理的值（camelTailTracking 和 lastTrackingValue 都是默认值）。
from("mongodb3:myDb?database=flights&collection=cancellations&tailTrackIncreasingField=departureTime&persistentTailTracking=true" +
"&persistentId=cancellationsTracker")
.id("tailableCursorConsumer2")
.autoStartup(false)
.to("mock:test");
from("mongodb3:myDb?database=flights&collection=cancellations&tailTrackIncreasingField=departureTime&persistentTailTracking=true" +
"&persistentId=cancellationsTracker")
.id("tailableCursorConsumer2")
.autoStartup(false)
.to("mock:test");以下是与以上地址相同的另一个示例，但永久跟踪运行时信息将存储在 "trackers.camelTrackers" 集合中，在"lastProcessedDepartureTime"字段中：
'%20d='M201.5%20305.5c-13.8%200-24.9-11.1-24.9-24.6%200-13.8%2011.1-24.9%2024.9-24.9%2013.6%200%2024.6%2011.1%2024.6%2024.9%200%2013.6-11.1%2024.6-24.6%2024.6zM504%20256c0%20137-111%20248-248%20248S8%20393%208%20256%20119%208%20256%208s248%20111%20248%20248zm-132.3-41.2c-9.4%200-17.7%203.9-23.8%2010-22.4-15.5-52.6-25.5-86.1-26.6l17.4-78.3%2055.4%2012.5c0%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.3%2024.9-24.9s-11.1-24.9-24.9-24.9c-9.7%200-18%205.8-22.1%2013.8l-61.2-13.6c-3-.8-6.1%201.4-6.9%204.4l-19.1%2086.4c-33.2%201.4-63.1%2011.3-85.5%2026.8-6.1-6.4-14.7-10.2-24.1-10.2-34.9%200-46.3%2046.9-14.4%2062.8-1.1%205-1.7%2010.2-1.7%2015.5%200%2052.6%2059.2%2095.2%20132%2095.2%2073.1%200%20132.3-42.6%20132.3-95.2%200-5.3-.6-10.8-1.9-15.8%2031.3-16%2019.8-62.5-14.9-62.5zM302.8%20331c-18.2%2018.2-76.1%2017.9-93.6%200-2.2-2.2-6.1-2.2-8.3%200-2.5%202.5-2.5%206.4%200%208.6%2022.8%2022.8%2087.3%2022.8%20110.2%200%202.5-2.2%202.5-6.1%200-8.6-2.2-2.2-6.1-2.2-8.3%200zm7.7-75c-13.6%200-24.6%2011.1-24.6%2024.9%200%2013.6%2011.1%2024.6%2024.6%2024.6%2013.8%200%2024.9-11.1%2024.9-24.6%200-13.8-11-24.9-24.9-24.9z'/%3e%3c/svg%3e){kind=small}