juicefs objbench list objects is slowly for ceph rados

[wutz]

juicefs objbench list objects is slowly

juicefs objbench --storage=ceph --access-key=ceph --secret-key=client.juicefs juicefs -p=1

Benchmark finished! block-size: 4.0 MiB, big-object-size: 1.0 GiB, small-object-size: 128 KiB, small-objects: 100, NumThreads: 1
+--------------------+------------------+-----------------+
|        ITEM        |       VALUE      |       COST      |
+--------------------+------------------+-----------------+
|     upload objects |     339.75 MiB/s | 11.77 ms/object |
|   download objects |     641.74 MiB/s |  6.23 ms/object |
|  put small objects |  403.5 objects/s |  2.48 ms/object |
|  get small objects | 1134.3 objects/s |  0.88 ms/object |
|       list objects | 142.85 objects/s |    700.05 ms/op |
|       head objects | 9414.6 objects/s |  0.11 ms/object |
|     delete objects | 1867.2 objects/s |  0.54 ms/object |
| change permissions |      not support |     not support |
| change owner/group |      not support |     not support |
|       update mtime |      not support |     not support |
+--------------------+------------------+-----------------+

rados bench

rados bench -n client.benchmark -p benchmark -b 4K 60 write --no-cleanup

Total time run:         60.0015
Total writes made:      1626073
Write size:             4096
Object size:            4096
Bandwidth (MB/sec):     105.861
Stddev Bandwidth:       0.672752
Max bandwidth (MB/sec): 107.492
Min bandwidth (MB/sec): 103.75
Average IOPS:           27100
Stddev IOPS:            172.225
Max IOPS:               27518
Min IOPS:               26560
Average Latency(s):     0.000589393
Stddev Latency(s):      0.000173608
Max latency(s):         0.0318762
Min latency(s):         0.000360764

time rados -n client.benchmark -p benchmark ls |wc -l
1626076

real	0m5.500s
user	0m0.792s
sys	0m2.204s