文章目录简介启用区域回收服务
前言
笔者以前写过关于Ozone数据勘探服务Recon的报道。 存储系统“数据眼睛”设计-数据勘探服务大致介绍了Recon如何通过定期获取OM快照来进行数据的二次分析。 但是，我们没有介绍Recon服务是如何启用的，以及该服务启用后在内部是如何工作的。 本文补充介绍这个内容。
要为区域恢复服务启用区域恢复服务，必须依赖元数据。 通过定期同步om元数据数据库来完成。 因此，这里需要为Recon服务设置OM的通信地址，这里是OM的http地址(这里是默认端口9874 )。
property name ozone.om.http -地址/name value { om host } :9874/value/property以及recon db、recon om db的存储目录
property name ozone.recon.db.dir/name value/path/to/recon.db/value/propertypropertynameozone.recon.om .
property name recon.om.snapshot.task.interval.delay/name value 3m/value/property检查上述配置并完成配置后，启动recon服务，然后单击
~/Apache/ozone/fkd yj/ozone--在daemonstartrecon和recon日志中可以清楚地看到其内部执行的操作。
2019-12-1507336028336033，697 [主] info-startingreconserver 2019-12-1507336028336034， 921 [ main ] info-registeredtaskcontainerkeymappertaskwithcontroller.2019-12-1507336028:35，178 [ main ] info-registeredtaskfilesizecounttaskwithcontroller.2019-12-1507336028336035，341 [ main ] warn-ozone.recon.om.db.dirisnotconfigured.werecommendaddingthissetting.fallingbacktoozone.metadata.dirirsinsted 539 [主] info-startingreconommetadatamanagerimpl 2019-12-1507336028336035， 539[主要] warn-ozone.recon.om.db.dirisnotconfigured.werecommendaddingthissetting.fallingbacktoozone.metadata 541 [ pool-8-thread-1 ] info-syncingdatafromozonemanager.2019-12-1507336029:35， 542 [ pool-8-thread-1 ] info-obtainingfullsnapshotfromozonemanager 2019-12-1507336029:36， 917 [ pool-8-thread-1 ] info-gotnewcheckpointfromom :/home/HDFS/data/meta/om.snapshot.db _ 157653765284; 157654204
tasks.2019-12-15 07:29:37,345 [pool-6-thread-1] INFO - Starting a 'reprocess' run of ContainerKeyMapperTask.2019-12-15 07:29:37,939 [pool-6-thread-1] INFO - Creating new Recon Container DB at /home/hdfs/data/meta/recon.db/recon-container.db_15764201773462019-12-15 07:29:37,940 [pool-6-thread-1] INFO - Cleaning up old Recon Container DB at /home/hdfs/data/meta/recon.db/recon-container.db_1576384466698.2019-12-15 07:29:37,997 [pool-6-thread-1] INFO - Completed 'reprocess' of ContainerKeyMapperTask.2019-12-15 07:29:37,998 [pool-6-thread-1] INFO - It took me 0.651 seconds to process 0 keys.201因为上述recon server在启动时，笔者没有创建任何的key文件，所以上面没有key被处理，但是recon db文件其实已经建立好了。
[hdfs@lyq meta]$ ls -l /home/hdfs/data/meta/recon.db/total 44drwxrwxr-x 2 hdfs hdfs 4096 Dec 14 08:42 om.db.checkpoints-rw-rw-r-- 1 hdfs hdfs 36864 Dec 16 07:19 ozone_recon_sqlite.dbdrwxr-xr-x 2 hdfs hdfs 4096 Dec 15 07:38 recon-container.db_1576420725643上面的ozone_recon_sqlite.db将会用来存储数据分析的汇总表数据。
OM Snapshot db文件，笔者测试时是放在另外一个目录上的，
然后我们用Ozone freon工具来随机创建少量的key文件，
[hdfs@lyq logs]$ ~/apache/ozone/fkdyj/ozone freon randomkeys --numOfVolumes=1 --numOfBuckets=1 --numOfKeys=2 --keySize=102402019-12-15 07:37:57,102 INFO impl.MetricsConfig: Loaded properties from hadoop-metrics2.properties2019-12-15 07:37:57,158 INFO impl.MetricsSystemImpl: Scheduled Metric snapshot period at 10 second(s).2019-12-15 07:37:57,158 INFO impl.MetricsSystemImpl: ozone-freon metrics system started2019-12-15 07:38:03,571 [main] INFO - Number of Threads: 102019-12-15 07:38:03,574 [main] INFO - Number of Volumes: 1.2019-12-15 07:38:03,575 [main] INFO - Number of Buckets per Volume: 1.2019-12-15 07:38:03,575 [main] INFO - Number of Keys per Bucket: 2.2019-12-15 07:38:03,575 [main] INFO - Key size: 10240 bytes2019-12-15 07:38:03,575 [main] INFO - Buffer size: 4096 bytes2019-12-15 07:38:03,575 [main] INFO - validateWrites : false2019-12-15 07:38:03,585 [main] INFO - Starting progress bar Thread. 0.00% |? | 0/2 Time: 0:00:002019-12-15 07:38:03,600 [pool-2-thread-2] INFO - Creating Volume: vol-0-85226, with hdfs as owner.2019-12-15 07:38:04,107 [pool-2-thread-1] INFO - Creating Bucket: vol-0-85226/bucket-0-19333, with Versioning false and Storage Type set to DISK and Encryption set to false 0.00% |? | 0/2 Time: 0:00:012019-12-15 07:38:04,839 WARN impl.MetricsSystemImpl: ozone-freon metrics system already initialized! 0.00% |? | 50.00% |??????????????????????????????????????????????????? 100.00% |?????????????????????????????????????????????????????????????????????????????????????????????????????| 2/2 Time: 0:00:04***************************************************Status: SuccessGit Base Revision: e97acb3bd8f3befd27418996fa5d4b50bf2e17bfNumber of Volumes created: 1Number of Buckets created: 1Number of Keys added: 2Ratis replication factor: ONERatis replication type: STAND_ALONEAverage Time spent in volume creation: 00:00:00,048Average Time spent in bucket creation: 00:00:00,006Average Time spent in key creation: 00:00:00,056Average Time spent in key write: 00:00:00,441Total bytes written: 20480Total Execution time: 00:00:11,299***************************************************然后我们在下一次OM db文件的同步处理过程中，就能够看到新的被写入的key正在被处理了。
2019-12-15 07:38:45,421 [pool-8-thread-1] INFO - Created OM DB snapshot at /home/hdfs/data/meta/om.snapshot.db_1576420724252.2019-12-15 07:38:45,642 [pool-8-thread-1] INFO - Calling reprocess on Recon tasks.2019-12-15 07:38:45,643 [pool-6-thread-1] INFO - Starting a 'reprocess' run of ContainerKeyMapperTask.2019-12-15 07:38:46,272 [pool-6-thread-1] INFO - Creating new Recon Container DB at /home/hdfs/data/meta/recon.db/recon-container.db_15764207256432019-12-15 07:38:46,272 [pool-6-thread-1] INFO - Cleaning up old Recon Container DB at /home/hdfs/data/meta/recon.db/recon-container.db_1576420543845.2019-12-15 07:38:46,875 [pool-6-thread-1] INFO - Completed 'reprocess' of ContainerKeyMapperTask.2019-12-15 07:38:46,876 [pool-6-thread-1] INFO - It took me 1.233 seconds to process 2 keys.2019-12-15 07:38:47,303 [pool-6-thread-1] INFO - Completed a 'reprocess' run of FileSizeCountTask.但目前这些分析结果数据只是被写入ozone_recon_sqlite.db，还没有很好地展现给外部使用，这块功能后续应该会完善许多。目前Recon Server的UI只是一个简单的页面展示，后续会做更多数据的集成。大家可以继续关注Recon的后续进展，目前Ozone社区已经在实现Recon 2.0阶段的工作了。下图为Recon的web UI: