#!/usr/bin/python2 import subprocess import json import sys from argparse import * class cephCRUSH(): """ Currently, this script is coded to work with the ceph clusters that have these type-ids -- osd, host, rack, root. To add other type_ids to the CRUSH map, this script needs enhancements to include the new type_ids. type_id name ------- ---- 0 osd 1 host 2 chassis 3 rack 4 row 5 pdu 6 pod 7 room 8 datacenter 9 region 10 root Ceph organizes the CRUSH map in hierarchical topology. At the top, it is the root. The next levels are racks, hosts, and OSDs, respectively. The OSDs are at the leaf level. This script looks at OSDs in each placement group of a ceph pool. For each OSD, starting from the OSD leaf level, this script traverses up to the root. Along the way, the host and rack are recorded and then verified to make sure the paths to the root are in separate failure domains. This script reports the offending PGs to stdout. """ """ This list stores the ceph crush hierarchy retrieved from the ceph osd crush tree -f json-pretty """ crushHierarchy = [] """ Failure Domains - currently our crush map uses these type IDs - osd, host, rack, root If we need to add chassis type (or other types) later on, add the type to the if statement in the crushFD construction section. crushFD[0] = {'id': -2, 'name': 'host1', 'type': 'host'} crushFD[23] = {'id': -5, 'name': 'host2', 'type': 'host'} crushFD[68] = {'id': -7, 'name': 'host3', 'type': 'host'} rack_FD[-2] = {'id': -9, 'name': 'rack1', 'type': 'rack' } rack_FD[-15] = {'id': -17, 'name': 'rack2', 'type': 'rack' } root_FD[-17] = {'id': -1, 'name': 'default', 'type': 'root' }} root_FD[-9] = {'id': -1, 'name': 'default', 'type': 'root' }} """ crushFD = {} def __init__(self, poolName): if 'all' in poolName or 'All' in poolName: try: poolLs = 'ceph osd pool ls -f json-pretty' poolstr = subprocess.check_output(poolLs, shell=True) self.listPoolName = json.loads(poolstr) except subprocess.CalledProcessError as e: print('{}'.format(e)) """Unable to get all pools - cannot proceed""" sys.exit(2) else: self.listPoolName = poolName try: """Retrieve the crush hierarchies""" crushTree = "ceph osd crush tree -f json-pretty | grep -v '^\[\]'" chstr = subprocess.check_output(crushTree, shell=True) self.crushHierarchy = json.loads(chstr) except subprocess.CalledProcessError as e: print('{}'.format(e)) """Unable to get crush hierarchy - cannot proceed""" sys.exit(2) """ Number of racks configured in the ceph cluster. The racks that are present in the crush hierarchy may not be used. The un-used rack would not show up in the crushFD. """ self.count_racks = 0 """depth level - 3 is OSD, 2 is host, 1 is rack, 0 is root""" self.osd_depth = 0 """Construct the Failure Domains - OSD -> Host -> Rack -> Root""" for chitem in self.crushHierarchy: if chitem['type'] == 'host' or \ chitem['type'] == 'rack' or \ chitem['type'] == 'root': for child in chitem['children']: self.crushFD[child] = {'id': chitem['id'], 'name': chitem['name'], 'type': chitem['type']} if chitem['type'] == 'rack' and len(chitem['children']) > 0: self.count_racks += 1 elif chitem['type'] == 'osd': if self.osd_depth == 0: self.osd_depth = chitem['depth'] """[ { 'pg-name' : [osd.1, osd.2, osd.3] } ... ]""" self.poolPGs = [] """Replica of the pool. Initialize to 0.""" self.poolSize = 0 def getPoolSize(self, poolName): """ size (number of replica) is an attribute of a pool { "pool": "rbd", "pool_id": 1, "size": 3 } """ pSize = {} """Get the size attribute of the poolName""" try: poolGet = 'ceph osd pool get ' + poolName + ' size -f json-pretty' szstr = subprocess.check_output(poolGet, shell=True) pSize = json.loads(szstr) self.poolSize = pSize['size'] except subprocess.CalledProcessError as e: print('{}'.format(e)) self.poolSize = 0 """Continue on""" return def checkPGs(self, poolName): if not len(self.poolPGs) > 0: return print('Checking PGs in pool {} ...'.format(poolName)), badPGs = False for pg in self.poolPGs: osdUp = pg['up'] """ Construct the OSD path from the leaf to the root. If the replica is set to 3 and there are 3 racks. Each OSD has its own rack (failure domain). If more than one OSD has the same rack, this is a violation. If the number of rack is one, then we need to make sure the hosts for the three OSDs are different. """ check_FD = {} checkFailed = False for osd in osdUp: traverseID = osd """Start the level with 1 to include the OSD leaf""" traverseLevel = 1 while (self.crushFD[traverseID]['type'] != 'root'): crushType = self.crushFD[traverseID]['type'] crushName = self.crushFD[traverseID]['name'] if crushType in check_FD: check_FD[crushType].append(crushName) else: check_FD[crushType] = [crushName] """traverse up (to the root) one level""" traverseID = self.crushFD[traverseID]['id'] traverseLevel += 1 assert (traverseLevel == self.osd_depth), "OSD depth mismatch" """ check_FD should have { 'host': ['host1', 'host2', 'host3', 'host4'], 'rack': ['rack1', 'rack2', 'rack3'] } Not checking for the 'root' as there is only one root. """ for ktype in check_FD: kvalue = check_FD[ktype] if ktype == 'host': """ At the host level, every OSD should come from different host. It is a violation if duplicate hosts are found. """ if len(kvalue) != len(set(kvalue)): if not badPGs: print('Failed') badPGs = True print('OSDs {} in PG {} failed check in host {}'.format(pg['up'], pg['pgid'], kvalue)) elif ktype == 'rack': if len(kvalue) == len(set(kvalue)): continue else: """ There are duplicate racks. This could be due to situation like pool's size is 3 and there are only two racks (or one rack). OSDs should come from different hosts as verified in the 'host' section. """ if self.count_racks == len(set(kvalue)): continue elif self.count_racks > len(set(kvalue)): """Not all the racks were used to allocate OSDs""" if not badPGs: print('Failed') badPGs = True print('OSDs {} in PG {} failed check in rack {}'.format(pg['up'], pg['pgid'], kvalue)) check_FD.clear() if not badPGs: print('Passed') return def checkPoolPGs(self): for pool in self.listPoolName: self.getPoolSize(pool) if self.poolSize == 1: """No need to check pool with the size set to 1 copy""" print('Checking PGs in pool {} ... {}'.format(pool, 'Skipped')) continue elif self.poolSize == 0: print('Pool {} was not found.'.format(pool)) continue assert (self.poolSize > 1), "Pool size was incorrectly set" try: """Get the list of PGs in the pool""" lsByPool = 'ceph pg ls-by-pool ' + pool + ' -f json-pretty' pgstr = subprocess.check_output(lsByPool, shell=True) self.poolPGs = json.loads(pgstr) """Check that OSDs in the PG are in separate failure domains""" self.checkPGs(pool) except subprocess.CalledProcessError as e: print('{}'.format(e)) """Continue to the next pool (if any)""" return def Main(): parser = ArgumentParser(description=''' Cross-check the OSDs assigned to the Placement Groups (PGs) of a ceph pool with the CRUSH topology. The cross-check compares the OSDs in a PG and verifies the OSDs reside in separate failure domains. PGs with OSDs in the same failure domain are flagged as violation. The offending PGs are printed to stdout. This CLI is executed on-demand on a ceph-mon pod. To invoke the CLI, you can specify one pool or list of pools to check. The special pool name All (or all) checks all the pools in the ceph cluster. ''', formatter_class=RawTextHelpFormatter) parser.add_argument('PoolName', type=str, nargs='+', help='List of pools (or All) to validate the PGs and OSDs mapping') args = parser.parse_args() if ('all' in args.PoolName or 'All' in args.PoolName) and len(args.PoolName) > 1: print('You only need to give one pool with special pool All') sys.exit(1) """ Retrieve the crush hierarchies and store it. Cross-check the OSDs in each PG searching for failure domain violation. """ ccm = cephCRUSH(args.PoolName) ccm.checkPoolPGs() if __name__ == '__main__': Main()