def test_stop(pyocf_ctx, mode: CacheMode, cls: CacheLineSize, with_flush: bool):
"""Stopping cache.
Check if cache is stopped properly in different modes with or without preceding flush operation.
"""
cache_device = Volume(Size.from_MiB(20))
core_device = Volume(Size.from_MiB(5))
cache = Cache.start_on_device(cache_device, cache_mode=mode, cache_line_size=cls)
core_exported = Core.using_device(core_device)
cache.add_core(core_exported)
cls_no = 10
run_io_and_cache_data_if_possible(core_exported, mode, cls, cls_no)
stats = cache.get_stats()
assert int(stats["conf"]["dirty"]) == (cls_no if mode.lazy_write() else 0),\
"Dirty data before MD5"
md5_exported_core = core_exported.exp_obj_md5()
if with_flush:
cache.flush()
cache.stop()
if mode.lazy_write() and not with_flush:
assert core_device.md5() != md5_exported_core, \
"MD5 check: core device vs exported object with dirty data"
else:
assert core_device.md5() == md5_exported_core, \
"MD5 check: core device vs exported object with clean data"
def check_stats_read_empty(exported_obj: Core, mode: CacheMode, cls: CacheLineSize):
stats = exported_obj.cache.get_stats()
assert stats["conf"]["cache_mode"] == mode, "Cache mode"
assert exported_obj.cache.device.get_stats()[IoDir.WRITE] == (1 if mode.read_insert() else 0), \
"Writes to cache device"
assert exported_obj.device.get_stats()[IoDir.READ] == 1, "Reads from core device"
assert stats["req"]["rd_full_misses"]["value"] == (0 if mode == CacheMode.PT else 1), \
"Read full misses"
assert stats["usage"]["occupancy"]["value"] == \
((cls / CacheLineSize.LINE_4KiB) if mode.read_insert() else 0), "Occupancy"
def check_stats_write_empty(exported_obj: Core, mode: CacheMode, cls: CacheLineSize):
stats = exported_obj.cache.get_stats()
assert stats["conf"]["cache_mode"] == mode, "Cache mode"
# TODO(ajrutkow): why 1 for WT ??
assert exported_obj.cache.device.get_stats()[IoDir.WRITE] == \
(2 if mode.lazy_write() else (1 if mode == CacheMode.WT else 0)), \
"Writes to cache device"
assert exported_obj.device.get_stats()[IoDir.WRITE] == (0 if mode.lazy_write() else 1), \
"Writes to core device"
assert stats["req"]["wr_full_misses"]["value"] == (1 if mode.write_insert() else 0), \
"Write full misses"
assert stats["usage"]["occupancy"]["value"] == \
((cls / CacheLineSize.LINE_4KiB) if mode.write_insert() else 0), \
"Occupancy"
def test_start_stop_multiple(pyocf_ctx):
"""Starting/stopping multiple caches.
Check whether OCF allows for starting multiple caches and stopping them in random order
"""
caches = []
caches_no = randrange(6, 11)
for i in range(1, caches_no):
cache_device = Volume(Size.from_MiB(20))
cache_name = f"cache{i}"
cache_mode = CacheMode(randrange(0, len(CacheMode)))
size = 4096 * 2**randrange(0, len(CacheLineSize))
cache_line_size = CacheLineSize(size)
cache = Cache.start_on_device(
cache_device,
name=cache_name,
cache_mode=cache_mode,
cache_line_size=cache_line_size)
caches.append(cache)
stats = cache.get_stats()
assert stats["conf"]["cache_mode"] == cache_mode, "Cache mode"
assert stats["conf"]["cache_line_size"] == cache_line_size, "Cache line size"
assert stats["conf"]["cache_name"] == cache_name, "Cache name"
caches.sort(key=lambda e: randrange(1000))
for cache in caches:
logger.info("Getting stats before stopping cache")
stats = cache.get_stats()
cache_name = stats["conf"]["cache_name"]
cache.stop()
assert get_cache_by_name(pyocf_ctx, cache_name) != 0, "Try getting cache after stopping it"
def check_stats_write_after_read(exported_obj: Core,
mode: CacheMode,
cls: CacheLineSize,
read_from_empty=False):
stats = exported_obj.cache.get_stats()
assert exported_obj.cache.device.get_stats()[IoDir.WRITE] == \
(0 if mode in {CacheMode.WI, CacheMode.PT} else
(2 if read_from_empty and mode.lazy_write() else 1)), \
"Writes to cache device"
assert exported_obj.device.get_stats()[IoDir.WRITE] == (0 if mode.lazy_write() else 1), \
"Writes to core device"
assert stats["req"]["wr_hits"]["value"] == \
(1 if (mode.read_insert() and mode != CacheMode.WI)
or (mode.write_insert() and not read_from_empty) else 0), \
"Write hits"
assert stats["usage"]["occupancy"]["value"] == \
(0 if mode in {CacheMode.WI, CacheMode.PT} else (cls / CacheLineSize.LINE_4KiB)), \
"Occupancy"
def check_md5_sums(exported_obj: Core, mode: CacheMode):
if mode.lazy_write():
assert exported_obj.device.md5() != exported_obj.exp_obj_md5(), \
"MD5 check: core device vs exported object without flush"
exported_obj.cache.flush()
assert exported_obj.device.md5() == exported_obj.exp_obj_md5(), \
"MD5 check: core device vs exported object after flush"
else:
assert exported_obj.device.md5() == exported_obj.exp_obj_md5(), \
"MD5 check: core device vs exported object"
def check_md5_sums(core: Core, mode: CacheMode):
if mode.lazy_write():
assert core.device.md5() != core.get_front_volume().md5(), \
"MD5 check: core device vs exported object without flush"
core.cache.flush()
assert core.device.md5() == core.get_front_volume().md5(), \
"MD5 check: core device vs exported object after flush"
else:
assert core.device.md5() == core.get_front_volume().md5(), \
"MD5 check: core device vs exported object"
def test_start_stop_incrementally(pyocf_ctx):
"""Starting/stopping multiple caches incrementally.
Check whether OCF behaves correctly when few caches at a time are
in turns added and removed (#added > #removed) until their number reaches limit,
and then proportions are reversed and number of caches gradually falls to 0.
"""
counter = count()
caches = []
caches_limit = 10
add = True
run = True
increase = True
while run:
if add:
for i in range(0,
randrange(3, 5) if increase else randrange(1, 3)):
cache_device = Volume(Size.from_MiB(20))
cache_name = f"cache{next(counter)}"
cache_mode = CacheMode(randrange(0, len(CacheMode)))
size = 4096 * 2**randrange(0, len(CacheLineSize))
cache_line_size = CacheLineSize(size)
cache = Cache.start_on_device(cache_device,
name=cache_name,
cache_mode=cache_mode,
cache_line_size=cache_line_size)
caches.append(cache)
stats = cache.get_stats()
assert stats["conf"]["cache_mode"] == cache_mode, "Cache mode"
assert stats["conf"][
"cache_line_size"] == cache_line_size, "Cache line size"
assert stats["conf"]["cache_name"] == cache_name, "Cache name"
if len(caches) == caches_limit:
increase = False
else:
for i in range(0,
randrange(1, 3) if increase else randrange(3, 5)):
if len(caches) == 0:
run = False
break
cache = caches.pop()
logger.info("Getting stats before stopping cache")
stats = cache.get_stats()
cache_name = stats["conf"]["cache_name"]
cache.stop()
assert get_cache_by_name(pyocf_ctx, cache_name) != 0, \
"Try getting cache after stopping it"
add = not add
def test_100_start_stop(pyocf_ctx):
"""Starting/stopping stress test.
Check OCF behaviour when cache is started and stopped continuously
"""
for i in range(1, 101):
cache_device = Volume(Size.from_MiB(20))
cache_mode = CacheMode(randrange(0, len(CacheMode)))
size = 4096 * 2**randrange(0, len(CacheLineSize))
cache_line_size = CacheLineSize(size)
cache = Cache.start_on_device(
cache_device,
cache_mode=cache_mode,
cache_line_size=cache_line_size)
stats = cache.get_stats()
assert stats["conf"]["cache_mode"] == cache_mode, "Cache mode"
assert stats["conf"]["cache_line_size"] == cache_line_size, "Cache line size"
assert stats["conf"]["cache_id"] == 1, "Cache id"
cache.stop()
assert get_cache_by_id(pyocf_ctx, 1) != 0, "Try getting cache after stopping it"
