X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=cleaner%2Fcleaner;h=1e564e83c45e5c79c6f009716901589af475bfb2;hb=524d3c03d2f3076a349768c177a0e523a7fb333e;hp=42aef0111639f54f91b0d002a543b93443c1ec58;hpb=8260042a674abb9f47a331963180cc3b3560885f;p=bluesky.git diff --git a/cleaner/cleaner b/cleaner/cleaner index 42aef01..1e564e8 100755 --- a/cleaner/cleaner +++ b/cleaner/cleaner @@ -10,9 +10,11 @@ import base64, os, re, struct, sys import boto +from boto.s3.key import Key # The BlueSky 'struct cloudlog_header' data type. -HEADER_FORMAT = '<4sb16sQIII' +HEADER_FORMAT = '<4s48sb16sQIII' +HEADER_CRYPTBYTES = 48 HEADER_MAGIC = 'AgI-' HEADER_SIZE = struct.calcsize(HEADER_FORMAT) @@ -49,9 +51,73 @@ class FileBackend: fp.write(data) fp.close() + def delete(self, filename): + os.unlink(os.path.join(self.path, filename)) + + def loc_to_name(self, location): + return "log-%08d-%08d" % (location) + + def name_to_loc(self, name): + m = re.match(r"^log-(\d+)-(\d+)$", name) + if m: return (int(m.group(1)), int(m.group(2))) + +class S3Backend: + """An interface to BlueSky where the log segments are on in Amazon S3.""" + + def __init__(self, bucket, path='', cachedir="."): + self.conn = boto.connect_s3(is_secure=False) + self.bucket = self.conn.get_bucket(bucket) + self.path = path + self.cachedir = cachedir + self.cache = {} + + def list(self): + files = [] + for k in self.bucket.list(self.path + 'log-'): + files.append((k.key, k.size)) + return files + + def read(self, filename): + if filename in self.cache: + fp = open(os.path.join(self.cachedir, filename), 'rb') + return fp.read() + else: + k = Key(self.bucket) + k.key = self.path + filename + data = k.get_contents_as_string() + fp = open(os.path.join(self.cachedir, filename), 'wb') + fp.write(data) + fp.close() + self.cache[filename] = True + return data + + def write(self, filename, data): + k = Key(self.bucket) + k.key = self.path + filename + k.set_contents_from_string(data) + if filename in self.cache: + del self.cache[filename] + + def delete(self, filename): + k = Key(self.bucket) + k.key = self.path + filename + k.delete() + if filename in self.cache: + del self.cache[filename] + + def loc_to_name(self, location): + return "log-%08d-%08d" % (location) + + def name_to_loc(self, name): + m = re.match(r"^log-(\d+)-(\d+)$", name) + if m: return (int(m.group(1)), int(m.group(2))) + class LogItem: """In-memory representation of a single item stored in a log file.""" + def __init__(self): + self.cryptkeys = '\0' * HEADER_CRYPTBYTES + def __str__(self): return "" % (self.type, self.location, self.size, base64.b16encode(self.id).lower()[0:8]) @@ -70,7 +136,8 @@ class LogItem: link_locs = ''.join(link_locs) header = struct.pack(HEADER_FORMAT, - HEADER_MAGIC, ord(self.type), self.id, self.inum, + HEADER_MAGIC, self.cryptkeys, + ord(self.type), self.id, self.inum, len(self.data), len(link_ids), len(link_locs)) return header + self.data + link_ids + link_locs @@ -91,18 +158,23 @@ class LogSegment: def close(self): data = ''.join(self.data) - filename = "log-%08d-%08d" % (self.location) + filename = self.backend.loc_to_name(self.location) print "Would write %d bytes of data to %s" % (len(data), filename) self.backend.write(filename, data) class LogDirectory: TARGET_SIZE = 4 << 20 - def __init__(self, backend, dir, seq): + def __init__(self, backend, dir): self.backend = backend self.dir_num = dir - self.seq_num = seq + self.seq_num = 0 + for logname in backend.list(): + loc = backend.name_to_loc(logname[0]) + if loc is not None and loc[0] == dir: + self.seq_num = max(self.seq_num, loc[1] + 1) self.groups = {} + print "Starting sequence number is", self.seq_num def open_segment(self): seg = LogSegment(self.backend, (self.dir_num, self.seq_num)) @@ -144,28 +216,29 @@ class UtilizationTracker: def parse_item(data): if len(data) < HEADER_SIZE: return header = struct.unpack_from(HEADER_FORMAT, data, 0) - size = HEADER_SIZE + sum(header[4:7]) + size = HEADER_SIZE + sum(header[5:8]) if header[0] != HEADER_MAGIC: print "Bad header magic!" return if len(data) != size: - print "Item size does not match!" + print "Item size does not match: %d != %d" % (size, len(data)) return item = LogItem() - item.id = header[2] - item.inum = header[3] + item.cryptkeys = header[1] + item.id = header[3] + item.inum = header[4] item.location = None - item.type = chr(header[1]) + item.type = chr(header[2]) item.size = size - item.data = data[HEADER_SIZE : HEADER_SIZE + header[4]] + item.data = data[HEADER_SIZE : HEADER_SIZE + header[5]] links = [] - link_ids = data[HEADER_SIZE + header[4] - : HEADER_SIZE + header[4] + header[5]] - link_locs = data[HEADER_SIZE + header[4] + header[5] - : HEADER_SIZE + sum(header[4:7])] + link_ids = data[HEADER_SIZE + header[5] + : HEADER_SIZE + header[5] + header[6]] + link_locs = data[HEADER_SIZE + header[5] + header[6] + : HEADER_SIZE + sum(header[5:8])] for i in range(len(link_ids) // 16): id = link_ids[16*i : 16*i + 16] if id == '\0' * 16: @@ -182,7 +255,7 @@ def load_item(backend, location): The elements of the tuple are (directory, sequence, offset, size).""" - filename = "log-%08d-%08d" % (location[0], location[1]) + filename = backend.loc_to_name((location[0], location[1])) data = backend.read(filename)[location[2] : location[2] + location[3]] item = parse_item(data) item.location = location @@ -201,7 +274,7 @@ def parse_log(data, location=None): offset = 0 while len(data) - offset >= HEADER_SIZE: header = struct.unpack_from(HEADER_FORMAT, data, offset) - size = HEADER_SIZE + sum(header[4:7]) + size = HEADER_SIZE + sum(header[5:8]) if header[0] != HEADER_MAGIC: print "Bad header magic!" break @@ -217,6 +290,7 @@ def parse_log(data, location=None): def load_checkpoint_record(backend): for (log, size) in reversed(backend.list()): for item in reversed(list(parse_log(backend.read(log), log))): + print item if item.type == ITEM_TYPE.CHECKPOINT: return item @@ -256,8 +330,10 @@ class InodeMap: print print "Segment utilizations:" for (s, u) in sorted(util.segments.items()): - #if u[1] > 0: print "%s: %s %s" % (s, u, float(u[1]) / u[0]) + if u[1] == 0: + print "Deleting..." + backend.delete(s) self.inodes = inodes self.util = util @@ -313,14 +389,15 @@ class InodeMap: log.write(new_checkpoint, 2) self.checkpoint_record = new_checkpoint -def rewrite_inode(backend, inode_map, inum, log): +def rewrite_inode(backend, inode_map, inum, log, copy_data=True): inode = inode_map.inodes[inum] - blocks = [] - for l in inode.links: - data = load_item(backend, l[1]) - blocks.append(data) - log.write(data, 0) - inode.links = [(b.id, b.location) for b in blocks] + if copy_data: + blocks = [] + for l in inode.links: + data = load_item(backend, l[1]) + blocks.append(data) + log.write(data, 0) + inode.links = [(b.id, b.location) for b in blocks] log.write(inode, 1) inode_map.mark_updated(inum) @@ -328,35 +405,48 @@ def run_cleaner(backend, inode_map, log): # Determine which segments are poorly utilized and should be cleaned. We # need better heuristics here. for (s, u) in sorted(inode_map.util.segments.items()): - if float(u[1]) / u[0] < 0.99 and u[1] > 0: + if (float(u[1]) / u[0] < 0.6 or u[1] < 32768) and u[1] > 0: print "Should clean segment", s - m = re.match(r"^log-(\d+)-(\d+)$", s) - if m: inode_map.obsolete_segments.add((int(m.group(1)), int(m.group(2)))) + loc = backend.name_to_loc(s) + if s: inode_map.obsolete_segments.add(loc) + + # TODO: We probably also want heuristics that will find inodes with + # badly-fragmented data and rewrite that to achieve better locality. # Given that list of segments to clean, scan through those segments to find # data which is still live and mark relevant inodes as needing to be # rewritten. dirty_inodes = set() + dirty_inode_data = set() for s in inode_map.obsolete_segments: - filename = "log-%08d-%08d" % s + filename = backend.loc_to_name(s) print "Scanning", filename, "for live data" for item in parse_log(backend.read(filename), filename): if item.type in (ITEM_TYPE.DATA, ITEM_TYPE.INODE): if item.inum != 0: - dirty_inodes.add(item.inum) + inode = inode_map.inodes[item.inum] + if s == inode.location[0:2]: + dirty_inodes.add(item.inum) + if item.inum not in dirty_inode_data: + for b in inode.links: + if s == b[1][0:2]: + dirty_inode_data.add(item.inum) + break print "Inodes to rewrite:", dirty_inodes - for i in sorted(dirty_inodes): - rewrite_inode(backend, inode_map, i, log) + print "Inodes with data to rewrite:", dirty_inode_data + for i in sorted(dirty_inodes.union(dirty_inode_data)): + rewrite_inode(backend, inode_map, i, log, i in dirty_inode_data) if __name__ == '__main__': - backend = FileBackend(".") + backend = S3Backend("mvrable-bluesky", cachedir=".") chkpt = load_checkpoint_record(backend) + print backend.list() imap = InodeMap() imap.build(backend, chkpt) print chkpt - log_dir = LogDirectory(backend, 1, 0) + log_dir = LogDirectory(backend, 0) run_cleaner(backend, imap, log_dir) imap.write(backend, log_dir) log_dir.close_all()