Question

---

我们可以通过一个 Python 脚本，统计出每个 OSD 上分布了多少个 PG ，以此判断集群的数据分布是否均衡。

#!/usr/bin/env  python
import sys 
import os
import json
cmd = '''
ceph pg dump | awk ' /^pg_stat/ { col=1; while($col!="up") {col++}; col++ } /^[0-9a-f]+\.[0-9a-f]+/ {print $1,$col}'
'''
body = os.popen(cmd).read()
SUM = {}
for line in  body.split('\n'):
       if not line.strip():
        continue
       SUM[line.split()[0]] = json.loads(line.split()[1])
pool = set()
for  key in  SUM:
      pool.add(key.split('.')[0])
mapping = {}
for number in pool:
      for k,v in SUM.items():
        if k.split('.')[0] == number:
               if number in mapping:
                   mapping[number] += v
               else:
                   mapping[number] = v
MSG = """%(pool)-6s: %(pools)s | SUM
%(line)s
%(dy)s
%(line)s
%(sun)-6s: %(end)s |"""
pools = " ".join(['%(a)-6s' % {"a": x} for x in sorted(list(mapping))])
line = len(pools) + 20
MA = {}
OSD = []
for p in mapping:
    osd = sorted(list(set(mapping[p])))
    OSD += osd
    count = sum([mapping[p].count(x) for x in osd])
    osds = {}
    for x in osd:
        osds[x] = mapping[p].count(x)
    MA[p] = {"osd": osds, "count": count}
MA = sorted(MA.items(), key=lambda x:x[0])
OSD = sorted(list(set(OSD)))
DY = ""
for osd in OSD:
    count = sum([x[1]["osd"].get(osd,0) for x in MA])
    w = ["%(x)-6s" % {"x": x[1]["osd"].get(osd,0)} for x in MA]
    #print w
    w.append("| %(x)-6s" % {"x": count})
    DY += 'osd.%(osd)-3s %(osds)s\n' % {"osd": osd, "osds": " ".join(w)}
SUM = " ".join(["%(x)-6s" % {"x": x[1]["count"]} for x in MA])
msg = {"pool": "pool", "pools": pools, "line": "-" * line, "dy": DY, "end": SUM, "sun": "SUM"}
print MSG % msg

执行效果如下：

root@OPS-ceph1:~# ./cal_pg_per_osd.py 
dumped all in format plain
pool  : 0      1      2      3      4      5      7      | SUM
--------------------------------------------------------------------
osd.0   2      9      11     10     5      6      1      | 44    
osd.1   1      7      8      10     8      9      3      | 46    
osd.2   2      11     7      6      6      8      4      | 44    
osd.3   1      11     7      9      7      4      1      | 40    
osd.4   2      12     12     12     11     13     0      | 62    
osd.5   2      10     10     5      9      11     0      | 47    
osd.6   3      56     47     49     38     43     16     | 252   
osd.7   6      36     48     45     55     42     10     | 242   
osd.8   4      41     42     37     35     49     15     | 223   
osd.9   6      42     52     41     55     36     12     | 244   
osd.10  10     36     47     51     39     43     15     | 241   
osd.11  6      56     47     44     41     46     12     | 252   
osd.12  6      40     45     45     51     46     11     | 244   
osd.13  6      42     40     56     46     44     9      | 243   
osd.14  5      44     41     49     48     52     7      | 246   
osd.15  4      50     42     38     49     38     12     | 233   
osd.16  3      9      5      11     8      8      2      | 46    
osd.17  2      10     13     4      7      10     2      | 48    
osd.18  0      12     10     10     10     9      6      | 57    
osd.19  0      13     8      4      9      15     2      | 51    
osd.20  1      11     7      9      9      15     2      | 54    
osd.21  0      7      12     10     6      12     1      | 48    
osd.22  4      39     45     30     43     46     12     | 219   
osd.23  6      44     38     44     38     41     6      | 217   
osd.24  7      37     50     49     49     36     8      | 236   
osd.25  10     28     38     44     40     32     11     | 203   
osd.26  1      44     33     47     47     37     13     | 222   
osd.27  3      47     38     42     44     55     14     | 243   
osd.28  4      47     47     34     33     48     11     | 224   
osd.29  3      40     32     34     40     51     10     | 210   
osd.30  8      39     46     47     55     35     10     | 240   
osd.31  5      48     48     45     41     36     11     | 234   
osd.32  5      46     48     53     42     48     7      | 249   
--------------------------------------------------------------------
SUM   : 128    1024   1024   1024   1024   1024   256    |