1 .TH "MEMASLAP" "1" "April 09, 2011" "0.47" "libmemcached"
3 memaslap \- libmemcached Documentation
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40 \fBmemaslap\fP is a load generation and benchmark tool for memcached(1)
41 servers. It generates configurable workload such as threads, concurrencies, connections,
42 run time, overwrite, miss rate, key size, value size, get/set proportion,
43 expected throughput, and so on. Furthermore, it also testss data
44 verification, expire\-time verification, UDP, binary protocol, facebook test,
45 replication test, multi\-get and reconnection, etc.
47 Memslap manages network connections like memcached with
48 libevent. Each thread of memaslap is bound with a CPU core, all
49 the threads don\(aqt communicate with each other, and there are several socket
50 connections in each thread. Each connection keeps key size distribution,
51 value size distribution, and command distribution by itself.
53 You can specify servers via the \fB\-\-servers\fP option or via the
54 environment variable \fBMEMCACHED_SERVERS\fP.
57 Memslap is developed to for the following purposes:
59 Manages network connections with libevent asynchronously.
61 Set both TCP and UDP up to use non\-blocking IO.
63 Improves parallelism: higher performance in multi\-threads environments.
65 Improves time efficiency: faster processing speed.
67 Generates key and value more efficiently; key size distribution and value size distribution are configurable.
69 Supports get, multi\-get, and set commands; command distribution is configurable.
71 Supports controllable miss rate and overwrite rate.
73 Supports data and expire\-time verification.
75 Supports dumping statistic information periodically.
77 Supports thousands of TCP connections.
79 Supports binary protocol.
81 Supports facebook test (set with TCP and multi\-get with UDP) and replication test.
83 .SS Effective implementation of network.
85 For memaslap, both TCP and UDP use non\-blocking network IO. All
86 the network events are managed by libevent as memcached. The network module
87 of memaslap is similar to memcached. Libevent can ensure
88 memaslap can handle network very efficiently.
89 .SS Effective implementation of multi\-threads and concurrency
91 Memslap has the similar implementation of multi\-threads to
92 memcached. Memslap creates one or more self\-governed threads;
93 each thread is bound with one CPU core if the system testss setting CPU
96 In addition, each thread has a libevent to manage the events of the network;
97 each thread has one or more self\-governed concurrencies; and each
98 concurrency has one or more socket connections. All the concurrencies don’t
99 communicate with each other even though they are in the same thread.
101 Memslap can create thousands of socket connections, and each
102 concurrency has tens of socket connections. Each concurrency randomly or
103 sequentially selects one socket connection from its socket connection pool
104 to run, so memaslap can ensure each concurrency handles one
105 socket connection at any given time. Users can specify the number of
106 concurrency and socket connections of each concurrency according to their
108 .SS Effective implementation of generating key and value
110 In order to improve time efficiency and space efficiency,
111 memaslap creates a random characters table with 10M characters. All the
112 suffixes of keys and values are generated from this random characters table.
114 Memslap uses the offset in the character table and the length
115 of the string to identify a string. It can save much memory.
116 Each key contains two parts, a prefix and a suffix. The prefix is an
117 uint64_t, 8 bytes. In order to verify the data set before,
118 memaslap need to ensure each key is unique, so it uses the prefix to identify
119 a key. The prefix cannot include illegal characters, such as ‘r’, ‘n’,
120 ‘0’ and ‘ ‘. And memaslap has an algorithm to ensure that.
122 Memslap doesn’t generate all the objects (key\-value pairs) at
123 the beginning. It only generates enough objects to fill the task window
124 (default 10K objects) of each concurrency. Each object has the following
125 basic information, key prefix, key suffix offset in the character table, key
126 length, value offset in the character table, and value length.
128 In the work process, each concurrency sequentially or randomly selects an
129 object from the window to do set operation or get operation. At the same
130 time, each concurrency kicks objects out of its window and adds new object
132 .SS Simple but useful task scheduling
134 Memslap uses libevent to schedule all the concurrencies of
135 threads, and each concurrency schedules tasks based on the local task
136 window. Memslap assumes that if each concurrency keeps the same
137 key distribution, value distribution and commands distribution, from
138 outside, memaslap keeps all the distribution as a whole.
139 Each task window includes a lot of objects, each object stores its basic
140 information, such as key, value, expire time, and so on. At any time, all
141 the objects in the window keep the same and fixed key and value
142 distribution. If an object is overwritten, the value of the object will be
143 updated. Memslap verifies the data or expire\-time according to
144 the object information stored in the task window.
146 Libevent selects which concurrency to handle based on a specific network
147 event. Then the concurrency selects which command (get or set) to operate
148 based on the command distribution. If it needs to kick out an old object and
149 add a new object, in order to keep the same key and value distribution, the
150 new object must have the same key length and value length.
152 If memcached server has two cache layers (memory and SSD), running
153 memaslap with different window sizes can get different cache
154 miss rates. If memaslap adds enough objects into the windows at
155 the beginning, and the cache of memcached cannot store all the objects
156 initialized, then memaslap will get some objects from the second
157 cache layer. It causes the first cache layer to miss. So the user can
158 specify the window size to get the expected miss rate of the first cache
160 .SS Useful implementation of multi\-servers , UDP, TCP, multi\-get and binary protocol
162 Because each thread is self\-governed, memaslap can assign
163 different threads to handle different memcached servers. This is just one of
164 the ways in which memaslap testss multiple servers. The only
165 limitation is that the number of servers cannot be greater than the number
166 of threads. The other way to tests multiple servers is for replication
167 test. Each concurrency has one socket connection to each memcached server.
168 For the implementation, memaslap can set some objects to one
169 memcached server, and get these objects from the other servers.
171 By default, Memslap does single get. If the user specifies
172 multi\-get option, memaslap will collect enough get commands and
173 pack and send the commands together.
175 Memslap testss both the ASCII protocol and binary protocol,
176 but it runs on the ASCII protocol by default.
177 Memslap by default runs on the TCP protocol, but it also
178 testss UDP. Because UDP is unreliable, dropped packages and out\-of\-order
179 packages may occur. Memslap creates a memory buffer to handle
180 these problems. Memslap tries to read all the response data of
181 one command from the server and reorders the response data. If some packages
182 get lost, the waiting timeout mechanism can ensure half\-baked packages will
183 be discarded and the next command will be sent.
186 Below are some usage samples:
188 memaslap \-s 127.0.0.1:11211 \-S 5s
190 memaslap \-s 127.0.0.1:11211 \-t 2m \-v 0.2 \-e 0.05 \-b
192 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-w 40k \-S 20s \-o 0.2
194 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-T 4 \-c 128 \-d 20 \-P 40k
196 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-d 50 \-a \-n 40
198 memaslap \-s 127.0.0.1:11211,127.0.0.1:11212 \-F config \-t 2m
200 memaslap \-s 127.0.0.1:11211,127.0.0.1:11212 \-F config \-t 2m \-p 2
202 The user must specify one server at least to run memaslap. The
203 rest of the parameters have default values, as shown below:
205 Thread number = 1 Concurrency = 16
207 Run time = 600 seconds Configuration file = NULL
209 Key size = 64 Value size = 1024
211 Get/set = 9:1 Window size = 10k
213 Execute number = 0 Single get = true
215 Multi\-get = false Number of sockets of each concurrency = 1
217 Reconnect = false Data verification = false
219 Expire\-time verification = false ASCII protocol = true
221 Binary protocol = false Dumping statistic information
225 Overwrite proportion = 0% UDP = false
227 TCP = true Limit throughput = false
229 Facebook test = false Replication test = false
230 .SS Key size, value size and command distribution.
232 All the distributions are read from the configuration file specified by user
233 with “—cfg_cmd” option. If the user does not specify a configuration file,
234 memaslap will run with the default distribution (key size = 64,
235 value size = 1024, get/set = 9:1). For information on how to edit the
236 configuration file, refer to the “Configuration File” section.
238 The minimum key size is 16 bytes; the maximum key size is 250 bytes. The
239 precision of proportion is 0.001. The proportion of distribution will be
240 rounded to 3 decimal places.
242 The minimum value size is 1 bytes; the maximum value size is 1M bytes. The
243 precision of proportion is 0.001. The proportion of distribution will be
244 rounded to 3 decimal places.
245 Currently, memaslap only testss set and get commands. And it
246 testss 100% set and 100% get. For 100% get, it will preset some objects to
248 .SS Multi\-thread and concurrency
250 The high performance of memaslap benefits from the special
251 schedule of thread and concurrency. It’s important to specify the proper
252 number of them. The default number of threads is 1; the default number of
253 concurrency is 16. The user can use “—threads” and “\-\-concurrency” to
254 specify these variables.
256 If the system testss setting CPU affinity and the number of threads
257 specified by the user is greater than 1, memaslap will try to
258 bind each thread to a different CPU core. So if you want to get the best
259 performance memaslap, it is better to specify the number of
260 thread equal to the number of CPU cores. The number of threads specified by
261 the user can also be less or greater than the number of CPU cores. Because
262 of the limitation of implementation, the number of concurrencies could be
263 the multiple of the number of threads.
267 For 8 CPU cores system
272 \-\-threads=2 \-\-concurrency=128
274 \-\-threads=8 \-\-concurrency=128
276 \-\-threads=8 \-\-concurrency=256
278 \-\-threads=12 \-\-concurrency=144
282 For 16 CPU cores system
287 \-\-threads=8 \-\-concurrency=128
289 \-\-threads=16 \-\-concurrency=256
291 \-\-threads=16 \-\-concurrency=512
293 \-\-threads=24 \-\-concurrency=288
295 The memaslap performs very well, when
296 used to test the performance of memcached servers.
297 Most of the time, the bottleneck is the network or
298 the server. If for some reason the user wants to
299 limit the performance of memaslap, there
300 are two ways to do this:
302 Decrease the number of threads and concurrencies.
303 Use the option “\-\-tps” that memaslap
304 provides to limit the throughput. This option allows
305 the user to get the expected throughput. For
306 example, assume that the maximum throughput is 50
307 kops/s for a specific configuration, you can specify
308 the throughput equal to or less than the maximum
309 throughput using “\-\-tps” option.
312 Most of the time, the user does not need to specify the window size. The
313 default window size is 10k. For Schooner Memcached, the user can specify
314 different window sizes to get different cache miss rates based on the test
315 case. Memslap testss cache miss rate between 0% and 100%.
316 If you use this utility to test the performance of Schooner Memcached, you
317 can specify a proper window size to get the expected cache miss rate. The
318 formula for calculating window size is as follows:
320 Assume that the key size is 128 bytes, and the value size is 2048 bytes, and
323 1. Small cache cache_size=1M, 100% cache miss (all data get from SSD).
331 (1). cache miss rate 0%
335 (2). cache miss rate 5%
344 (1). cache miss rate 0%
354 The formula for calculating window size for cache miss rate 0%:
356 cache_size / concurrency / (key_size + value_size) * 0.5
358 The formula for calculating window size for cache miss rate 5%:
360 cache_size / concurrency / (key_size + value_size) * 0.7
363 Memslap testss both data verification and expire\-time
364 verification. The user can use "\-\-verify=" or "\-v" to specify the proportion
365 of data verification. In theory, it testss 100% data verification. The
366 user can use "\-\-exp_verify=" or "\-e" to specify the proportion of
367 expire\-time verification. In theory, it testss 100% expire\-time
368 verification. Specify the "\-\-verbose" options to get more detailed error
371 For example: \-\-exp_verify=0.01 –verify=0.1 , it means that 1% of the objects
372 set with expire\-time, 10% of the objects gotten will be verified. If the
373 objects are gotten, memaslap will verify the expire\-time and
375 .SS multi\-servers and multi\-config
377 Memslap testss multi\-servers based on self\-governed thread.
378 There is a limitation that the number of servers cannot be greater than the
379 number of threads. Memslap assigns one thread to handle one
380 server at least. The user can use the "\-\-servers=" or "\-s" option to specify
385 \-\-servers=10.1.1.1:11211,10.1.1.2:11212,10.1.1.3:11213 \-\-threads=6 \-\-concurrency=36
387 The above command means that there are 6 threads, with each thread having 6
388 concurrencies and that threads 0 and 3 handle server 0 (10.1.1.1); threads 1
389 and 4 handle server 1 (10.1.1.2); and thread 2 and 5 handle server 2
392 All the threads and concurrencies in memaslap are self\-governed.
394 So is memaslap. The user can start up several
395 memaslap instances. The user can run memaslap on different client
396 machines to communicate with the same memcached server at the same. It is
397 recommended that the user start different memaslap on different
398 machines using the same configuration.
399 .SS Run with execute number mode or time mode
401 The default memaslap runs with time mode. The default run time
402 is 10 minutes. If it times out, memaslap will exit. Do not
403 specify both execute number mode and time mode at the same time; just
408 \-\-time=30s (It means the test will run 30 seconds.)
410 \-\-execute_number=100000 (It means that after running 100000 commands, the test will exit.)
411 .SS Dump statistic information periodically.
413 The user can use "\-\-stat_freq=" or "\-S" to specify the frequency.
419 Memslap will dump the statistics of the commands (get and set) at the frequency of every 20
422 For more information on the format of dumping statistic information, refer to “Format of Output” section.
425 The user can use "\-\-division=" or "\-d" to specify multi\-get keys count.
426 Memslap by default does single get with TCP. Memslap also testss data
427 verification and expire\-time verification for multi\-get.
429 Memslap testss multi\-get with both TCP and UDP. Because of
430 the different implementation of the ASCII protocol and binary protocol,
431 there are some differences between the two. For the ASCII protocol,
432 memaslap sends one “multi\-get” to the server once. For the
433 binary protocol, memaslap sends several single get commands
434 together as “multi\-get” to the server.
437 Memslap testss both UDP and TCP. For TCP,
438 memaslap does not reconnect the memcached server if socket connections are
439 lost. If all the socket connections are lost or memcached server crashes,
440 memaslap will exit. If the user specifies the “\-\-reconnect”
441 option when socket connections are lost, it will reconnect them.
443 User can use “\-\-udp” to enable the UDP feature, but UDP comes with some
446 UDP cannot set data more than 1400 bytes.
448 UDP is not testsed by the binary protocol because the binary protocol of
449 memcached does not tests that.
451 UDP doesn’t tests reconnection.
454 Set data with TCP and multi\-get with UDP. Specify the following options:
456 "\-\-facebook \-\-division=50"
458 If you want to create thousands of TCP connections, specify the
460 "\-\-conn_sock=" option.
462 For example: \-\-facebook \-\-division=50 \-\-conn_sock=200
464 The above command means that memaslap will do facebook test,
465 each concurrency has 200 socket TCP connections and one UDP socket.
467 Memslap sets objects with the TCP socket, and multi\-gets 50
468 objects once with the UDP socket.
470 If you specify "\-\-division=50", the key size must be less that 25 bytes
471 because the UDP packet size is 1400 bytes.
474 For replication test, the user must specify at least two memcached servers.
475 The user can use “—rep_write=” option to enable feature.
479 \-\-servers=10.1.1.1:11211,10.1.1.2:11212 –rep_write=2
481 The above command means that there are 2 replication memcached servers,
482 memaslap will set objects to both server 0 and server 1, get
483 objects which are set to server 0 before from server 1, and also get objects
484 which are set to server 1 before from server 0. If server 0 crashes,
485 memaslap will only get objects from server 1. If server 0 comes
486 back to life again, memaslap will reconnect server 0. If both
487 server 0 and server 1 crash, memaslap will exit.
488 .SS Supports thousands of TCP connections
490 Start memaslap with "\-\-conn_sock=" or "\-n" to enable this
491 feature. Make sure that your system can tests opening thousands of files
492 and creating thousands of sockets. However, this feature does not tests
493 reconnection if sockets disconnect.
497 \-\-threads=8 \-\-concurrency=128 \-\-conn_sock=128
499 The above command means that memaslap starts up 8 threads, each
500 thread has 16 concurrencies, each concurrency has 128 TCP socket
501 connections, and the total number of TCP socket connections is 128 * 128 =
503 .SS Supports binary protocol
505 Start memaslap with "\-\-binary" or "\-B" options to enable this
506 feature. It testss all the above features except UDP, because the latest
507 memcached 1.3.3 does not implement binary UDP protocol.
513 Since memcached 1.3.3 doesn\(aqt implement binary UDP protocol,
514 memaslap does not tests UDP. In addition, memcached 1.3.3 does not tests
515 multi\-get. If you specify "\-\-division=50" option, it just sends 50 get
516 commands together as “mulit\-get” to the server.
517 .SH CONFIGURATION FILE
519 This section describes the format of the configuration file. By default
520 when no configuration file is specified memaslap reads the default
521 one located at ~/.memaslap.cnf.
523 Below is a sample configuration file:
527 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
528 #comments should start with \(aq#\(aq
530 #start_len end_len proportion
532 #key length range from start_len to end_len
533 #start_len must be equal to or greater than 16
534 #end_len must be equal to or less than 250
535 #start_len must be equal to or greater than end_len
536 #memaslap will generate keys according to the key range
537 #proportion: indicates keys generated from one range accounts for the total
540 #example1: key range 16~100 accounts for 80%
541 # key range 101~200 accounts for 10%
542 # key range 201~250 accounts for 10%
543 # total should be 1 (0.8+0.1+0.1 = 1)
549 #example2: all keys length are 128 bytes
555 #start_len end_len proportion
557 #value length range from start_len to end_len
558 #start_len must be equal to or greater than 1
559 #end_len must be equal to or less than 1M
560 #start_len must be equal to or greater than end_len
561 #memaslap will generate values according to the value range
562 #proportion: indicates values generated from one range accounts for the
563 total generated values
565 #example1: value range 1~1000 accounts for 80%
566 # value range 1001~10000 accounts for 10%
567 # value range 10001~100000 accounts for 10%
568 # total should be 1 (0.8+0.1+0.1 = 1)
574 #example2: all value length are 128 bytes
580 #cmd_type cmd_proportion
582 #currently memaslap only testss get and set command.
588 #example: set command accounts for 50%
589 # get command accounts for 50%
590 # total should be 1 (0.5+0.5 = 1)
602 At the beginning, memaslap displays some configuration information as follows:
604 servers : 127.0.0.1:11211
614 set proportion: set_prop=0.10
616 get proportion: get_prop=0.90
623 The servers used by memaslap.
631 The number of threads memaslap runs with.
639 The number of concurrencies memaslap runs with.
647 How long to run memaslap.
655 The task window size of each concurrency.
663 The proportion of set command.
671 The proportion of get command.
675 The output of dynamic statistics is something like this:
679 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
681 Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us)
682 Avg(us) Std_dev Geo_dist
683 Period 5 345826 69165 65.3 0 27 2198 203
685 Global 20 1257935 62896 71.8 0 26 3791 224
690 Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us)
691 Avg(us) Std_dev Geo_dist
692 Period 5 38425 7685 7.3 0 42 628 240
694 Global 20 139780 6989 8.0 0 37 3790 253
699 Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us)
700 Avg(us) Std_dev Geo_dist
701 Period 5 384252 76850 72.5 0 27 2198 207
703 Global 20 1397720 69886 79.7 0 26 3791 227
705 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
714 Statistics information of get command
722 Statistics information of set command
730 Statistics information of both get and set command
738 Result within a period
762 Throughput, operations/second
778 How many objects can’t be gotten
786 The minimum response time
794 The maximum response time
802 The average response time
810 Standard deviation of response time
818 Geometric distribution based on natural exponential function
822 At the end, memaslap will output something like this:
826 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
827 Get Statistics (1257956 events)
835 8: 484890 459823 12543 824
838 Set Statistics (139782 events)
846 8: 50784 65574 2064 167
849 Total Statistics (1397738 events)
857 8: 535674 525397 14607 991
867 written_bytes: 242516030
868 read_bytes: 1003702556
869 object_bytes: 152086080
874 Run time: 20.0s Ops: 1397754 TPS: 69817 Net_rate: 59.4M/s
875 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
884 Get statistics of response time
892 Set statistics of response time
900 Both get and set statistics of response time
908 The accumulated and minimum response time
916 The accumulated and maximum response time
924 The accumulated and average response time
932 Standard deviation of response time
940 Geometric distribution based on logarithm 2
948 Total get commands done
956 Total set commands done
964 How many objects can’t be gotten from server
972 How many objects need to verify but can’t get them
980 How many objects with insistent value
988 How many objects are expired but we get them
996 How many objects are unexpired but we can’t get them
1028 How many UDP packages are disorder
1036 How many UDP packages are lost
1044 How many times UDP time out happen
1068 Throughput, operations/second
1076 The average rate of network
1082 .B \-s, \-\-servers=
1084 List one or more servers to connect. Servers count must be less than
1085 threads count. e.g.: \-\-servers=localhost:1234,localhost:11211
1087 .B \-T, \-\-threads=
1089 Number of threads to startup, better equal to CPU numbers. Default 8.
1091 .B \-c, \-\-concurrency=
1093 Number of concurrency to simulate with load. Default 128.
1095 .B \-n, \-\-conn_sock=
1097 Number of TCP socks per concurrency. Default 1.
1099 .B \-x, \-\-execute_number=
1101 Number of operations(get and set) to execute for the
1102 given test. Default 1000000.
1106 How long the test to run, suffix: s\-seconds, m\-minutes, h\-hours,
1107 d\-days e.g.: \-\-time=2h.
1109 .B \-F, \-\-cfg_cmd=
1111 Load the configure file to get command,key and value distribution list.
1113 .B \-w, \-\-win_size=
1115 Task window size of each concurrency, suffix: K, M e.g.: \-\-win_size=10k.
1118 .B \-X, \-\-fixed_size=
1120 Fixed length of value.
1124 The proportion of date verification, e.g.: \-\-verify=0.01
1126 .B \-d, \-\-division=
1128 Number of keys to multi\-get once. Default 1, means single get.
1130 .B \-S, \-\-stat_freq=
1132 Frequency of dumping statistic information. suffix: s\-seconds,
1133 m\-minutes, e.g.: \-\-resp_freq=10s.
1135 .B \-e, \-\-exp_verify=
1137 The proportion of objects with expire time, e.g.: \-\-exp_verify=0.01.
1138 Default no object with expire time
1140 .B \-o, \-\-overwrite=
1142 The proportion of objects need overwrite, e.g.: \-\-overwrite=0.01.
1143 Default never overwrite object.
1147 .B \-R, \-\-reconnect
1149 Reconnect tests, when connection is closed it will be reconnected.
1153 UDP tests, default memaslap uses TCP, TCP port and UDP port of
1154 server must be same.
1156 .B \-a, \-\-facebook
1158 Whether it enables facebook test feature, set with TCP and multi\-get with UDP.
1162 Whether it enables binary protocol. Default with ASCII protocol.
1168 Expected throughput, suffix: K, e.g.: \-\-tps=10k.
1170 .B \-p, \-\-rep_write=
1172 The first nth servers can write data, e.g.: \-\-rep_write=2.
1178 Whether it outputs detailed information when verification fails.
1182 Display this message and then exit.
1186 Display the version of the application and then exit.
1190 memaslap \-s 127.0.0.1:11211 \-S 5s
1192 memaslap \-s 127.0.0.1:11211 \-t 2m \-v 0.2 \-e 0.05 \-b
1194 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-w 40k \-S 20s \-o 0.2
1196 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-T 4 \-c 128 \-d 20 \-P 40k
1198 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-d 50 \-a \-n 40
1200 memaslap \-s 127.0.0.1:11211,127.0.0.1:11212 \-F config \-t 2m
1202 memaslap \-s 127.0.0.1:11211,127.0.0.1:11212 \-F config \-t 2m \-p 2
1205 To find out more information please check:
1206 \fI\%http://launchpad.org/libmemcached\fP
1209 Mingqiang Zhuang <\fI\%mingqiangzhuang@hengtiansoft.com\fP> (Schooner Technolgy)
1210 Brian Aker, <\fI\%brian@tangent.org\fP>
1213 \fImemcached(1)\fP \fIlibmemcached(3)\fP
1217 2011, Brian Aker DataDifferential, http://datadifferential.com/
1218 .\" Generated by docutils manpage writer.