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provisioning: more repair/survivability data

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This commit is contained in:
Brian Warner 2007-09-06 22:54:53 -07:00
parent 69d680d820
commit 421277cafa
1 changed files with 60 additions and 13 deletions
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73
src/allmydata/provisioning.py
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@ -166,18 +166,23 @@ class ProvisioningTool(rend.Page):
" no convergence)", i_sharing_ratio)
# Encoding parameters
encoding_choices = [("3-of-10", "3.3x (3-of-10)"),
("5-of-10", "2x (5-of-10)"),
("8-of-10", "1.25x (8-of-10)"),
("25-of-100", "4x (25-of-100)"),
encoding_choices = [("3-of-10-5", "3.3x (3-of-10, repair below 5)"),
("3-of-10-8", "3.3x (3-of-10, repair below 8)"),
("5-of-10-7", "2x (5-of-10, repair below 7)"),
("8-of-10-9", "1.25x (8-of-10, repair below 9)"),
("25-of-100-50", "4x (25-of-100, repair below 50)"),
]
encoding_parameters, i_encoding_parameters = \
get_and_set("encoding_parameters",
encoding_choices, "3-of-10", str)
encoding_choices, "3-of-10-5", str)
encoding_pieces = encoding_parameters.split("-")
k = int(encoding_pieces[0])
assert encoding_pieces[1] == "of"
n = int(encoding_pieces[2])
# we repair the file when the number of available shares drops below
# this value
repair_threshold = int(encoding_pieces[3])
add_input("Servers",
"What are the default encoding parameters?",
i_encoding_parameters)
@ -308,6 +313,19 @@ class ProvisioningTool(rend.Page):
i_lease)
seconds_per_lease = 24*60*60*lease_timer
check_timer_choices = [ (1, "every week"),
(4, "every month"),
(8, "every two months"),
(16, "every four months"),
]
check_timer, i_check_timer = \
get_and_set("check_timer", check_timer_choices, 4, int)
add_input("Users",
"How frequently should we check on each file?",
i_check_timer)
file_check_interval = check_timer * 7 * 24 * 3600
if filled:
add_output("Users", T.div["Total users: %s" % number(num_users)])
add_output("Users",
@ -316,6 +334,7 @@ class ProvisioningTool(rend.Page):
add_output("Users",
T.div["Average file size: ", number(file_size)])
total_files = num_users * files_per_user / sharing_ratio
user_file_check_interval = file_check_interval / files_per_user
add_output("Grid",
T.div["Total number of files in grid: ",
@ -453,6 +472,14 @@ class ProvisioningTool(rend.Page):
" , bytes = ",
number(client_download_byte_rate, "Bps"),
])
total_file_check_rate = 1.0 * total_files / file_check_interval
client_check_share_rate = total_file_check_rate / num_users
add_output("Users",
T.div["file check rate: shares = ",
number(client_check_share_rate, "Hz"),
" (interval = %s)" %
number(1 / client_check_share_rate, "s"),
])
client_upload_share_rate = upload_rate * n
# TODO: doesn't include overhead
@ -475,6 +502,11 @@ class ProvisioningTool(rend.Page):
" , bytes = ",
number(server_inbound_byte_rate, "Bps"),
])
add_output("Servers",
T.div["share check rate (inbound): ",
number(total_file_check_rate * n / num_servers,
"Hz"),
])
server_share_modify_rate = ((client_upload_share_rate +
client_delete_share_rate) *
@ -520,6 +552,10 @@ class ProvisioningTool(rend.Page):
T.div[" %% share data: %.2f%%" %
(100.0 * share_data_per_server /
share_space_per_server)])
add_output("Grid",
T.div["file check rate: ",
number(total_file_check_rate,
"Hz")])
total_drives = mathutil.div_ceil(int(total_share_space),
int(drive_size))
@ -561,14 +597,25 @@ class ProvisioningTool(rend.Page):
T.div["share data loss rate: ",
number(share_data_loss_rate,"Bps")])
# assuming we choose to regenerate shares when they are halfway
# to failure, what is the rate of repair? Basically we need to
# regenerate all shares once every time_until_files_lost/2
repair_rate = total_space / (time_until_files_lost / 2)
add_output("Grid",
T.div["plaintext repair rate: ",
number(repair_rate, "Bps"),
" (repairing when file is halfway to lost time)"])
P_disk_failure_during_interval = (drive_failure_rate *
file_check_interval)
disk_failure_dBF = 10*math.log10(P_disk_failure_during_interval)
disk_failure_dBA = -disk_failure_dBF
file_survives_dBA = self.file_availability(k, repair_threshold,
disk_failure_dBA)
user_files_survives_dBA = self.many_files_availability( \
file_survives_dBA, files_per_user)
all_files_survives_dBA = self.many_files_availability( \
file_survives_dBA, total_files)
add_output("Users",
T.div["survival of: ",
"arbitrary file = %d dBA, " % file_survives_dBA,
"all files of user1 = %d dBA, " %
user_files_survives_dBA,
"all files in grid = %d dBA" %
all_files_survives_dBA,
])
all_sections = []