1 .TH "MEMASLAP" "1" "January 26, 2012" "1.0.3" "libmemcached"
3 memaslap \- libmemcached Documentation
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42 \fBmemaslap\fP is a load generation and benchmark tool for memcached
43 servers. It generates configurable workload such as threads, concurrencies,
44 connections, run time, overwrite, miss rate, key size, value size, get/set
45 proportion, expected throughput, and so on. Furthermore, it also testss data
46 verification, expire\-time verification, UDP, binary protocol, facebook test,
47 replication test, multi\-get and reconnection, etc.
49 Memaslap manages network connections like memcached with
50 libevent. Each thread of memaslap is bound with a CPU core, all
51 the threads don\(aqt communicate with each other, and there are several socket
52 connections in each thread. Each connection keeps key size distribution,
53 value size distribution, and command distribution by itself.
55 You can specify servers via the \fI\-\-servers\fP option or via the
56 environment variable \fBMEMCACHED_SERVERS\fP.
59 Memslap is developed to for the following purposes:
61 Manages network connections with libevent asynchronously.
63 Set both TCP and UDP up to use non\-blocking IO.
65 Improves parallelism: higher performance in multi\-threads environments.
67 Improves time efficiency: faster processing speed.
69 Generates key and value more efficiently; key size distribution and value size distribution are configurable.
71 Supports get, multi\-get, and set commands; command distribution is configurable.
73 Supports controllable miss rate and overwrite rate.
75 Supports data and expire\-time verification.
77 Supports dumping statistic information periodically.
79 Supports thousands of TCP connections.
81 Supports binary protocol.
83 Supports facebook test (set with TCP and multi\-get with UDP) and replication test.
85 .SS Effective implementation of network.
87 For memaslap, both TCP and UDP use non\-blocking network IO. All
88 the network events are managed by libevent as memcached. The network module
89 of memaslap is similar to memcached. Libevent can ensure
90 memaslap can handle network very efficiently.
91 .SS Effective implementation of multi\-threads and concurrency
93 Memslap has the similar implementation of multi\-threads to
94 memcached. Memslap creates one or more self\-governed threads;
95 each thread is bound with one CPU core if the system testss setting CPU
98 In addition, each thread has a libevent to manage the events of the network;
99 each thread has one or more self\-governed concurrencies; and each
100 concurrency has one or more socket connections. All the concurrencies don’t
101 communicate with each other even though they are in the same thread.
103 Memslap can create thousands of socket connections, and each
104 concurrency has tens of socket connections. Each concurrency randomly or
105 sequentially selects one socket connection from its socket connection pool
106 to run, so memaslap can ensure each concurrency handles one
107 socket connection at any given time. Users can specify the number of
108 concurrency and socket connections of each concurrency according to their
110 .SS Effective implementation of generating key and value
112 In order to improve time efficiency and space efficiency,
113 memaslap creates a random characters table with 10M characters. All the
114 suffixes of keys and values are generated from this random characters table.
116 Memslap uses the offset in the character table and the length
117 of the string to identify a string. It can save much memory.
118 Each key contains two parts, a prefix and a suffix. The prefix is an
119 uint64_t, 8 bytes. In order to verify the data set before,
120 memaslap need to ensure each key is unique, so it uses the prefix to identify
121 a key. The prefix cannot include illegal characters, such as ‘r’, ‘n’,
122 ‘0’ and ‘ ‘. And memaslap has an algorithm to ensure that.
124 Memslap doesn’t generate all the objects (key\-value pairs) at
125 the beginning. It only generates enough objects to fill the task window
126 (default 10K objects) of each concurrency. Each object has the following
127 basic information, key prefix, key suffix offset in the character table, key
128 length, value offset in the character table, and value length.
130 In the work process, each concurrency sequentially or randomly selects an
131 object from the window to do set operation or get operation. At the same
132 time, each concurrency kicks objects out of its window and adds new object
134 .SS Simple but useful task scheduling
136 Memslap uses libevent to schedule all the concurrencies of
137 threads, and each concurrency schedules tasks based on the local task
138 window. Memslap assumes that if each concurrency keeps the same
139 key distribution, value distribution and commands distribution, from
140 outside, memaslap keeps all the distribution as a whole.
141 Each task window includes a lot of objects, each object stores its basic
142 information, such as key, value, expire time, and so on. At any time, all
143 the objects in the window keep the same and fixed key and value
144 distribution. If an object is overwritten, the value of the object will be
145 updated. Memslap verifies the data or expire\-time according to
146 the object information stored in the task window.
148 Libevent selects which concurrency to handle based on a specific network
149 event. Then the concurrency selects which command (get or set) to operate
150 based on the command distribution. If it needs to kick out an old object and
151 add a new object, in order to keep the same key and value distribution, the
152 new object must have the same key length and value length.
154 If memcached server has two cache layers (memory and SSD), running
155 memaslap with different window sizes can get different cache
156 miss rates. If memaslap adds enough objects into the windows at
157 the beginning, and the cache of memcached cannot store all the objects
158 initialized, then memaslap will get some objects from the second
159 cache layer. It causes the first cache layer to miss. So the user can
160 specify the window size to get the expected miss rate of the first cache
162 .SS Useful implementation of multi\-servers , UDP, TCP, multi\-get and binary protocol
164 Because each thread is self\-governed, memaslap can assign
165 different threads to handle different memcached servers. This is just one of
166 the ways in which memaslap tests multiple servers. The only
167 limitation is that the number of servers cannot be greater than the number
168 of threads. The other way to test multiple servers is for replication
169 test. Each concurrency has one socket connection to each memcached server.
170 For the implementation, memaslap can set some objects to one
171 memcached server, and get these objects from the other servers.
173 By default, Memslap does single get. If the user specifies
174 multi\-get option, memaslap will collect enough get commands and
175 pack and send the commands together.
177 Memslap testss both the ASCII protocol and binary protocol,
178 but it runs on the ASCII protocol by default.
179 Memslap by default runs on the TCP protocol, but it also
180 tests UDP. Because UDP is unreliable, dropped packages and out\-of\-order
181 packages may occur. Memslap creates a memory buffer to handle
182 these problems. Memslap tries to read all the response data of
183 one command from the server and reorders the response data. If some packages
184 get lost, the waiting timeout mechanism can ensure half\-baked packages will
185 be discarded and the next command will be sent.
188 Below are some usage samples:
190 memaslap \-s 127.0.0.1:11211 \-S 5s
192 memaslap \-s 127.0.0.1:11211 \-t 2m \-v 0.2 \-e 0.05 \-b
194 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-w 40k \-S 20s \-o 0.2
196 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-T 4 \-c 128 \-d 20 \-P 40k
198 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-d 50 \-a \-n 40
200 memaslap \-s 127.0.0.1:11211,127.0.0.1:11212 \-F config \-t 2m
202 memaslap \-s 127.0.0.1:11211,127.0.0.1:11212 \-F config \-t 2m \-p 2
204 The user must specify one server at least to run memaslap. The
205 rest of the parameters have default values, as shown below:
207 Thread number = 1 Concurrency = 16
209 Run time = 600 seconds Configuration file = NULL
211 Key size = 64 Value size = 1024
213 Get/set = 9:1 Window size = 10k
215 Execute number = 0 Single get = true
217 Multi\-get = false Number of sockets of each concurrency = 1
219 Reconnect = false Data verification = false
221 Expire\-time verification = false ASCII protocol = true
223 Binary protocol = false Dumping statistic information
227 Overwrite proportion = 0% UDP = false
229 TCP = true Limit throughput = false
231 Facebook test = false Replication test = false
232 .SS Key size, value size and command distribution.
234 All the distributions are read from the configuration file specified by user
235 with “—cfg_cmd” option. If the user does not specify a configuration file,
236 memaslap will run with the default distribution (key size = 64,
237 value size = 1024, get/set = 9:1). For information on how to edit the
238 configuration file, refer to the “Configuration File” section.
240 The minimum key size is 16 bytes; the maximum key size is 250 bytes. The
241 precision of proportion is 0.001. The proportion of distribution will be
242 rounded to 3 decimal places.
244 The minimum value size is 1 bytes; the maximum value size is 1M bytes. The
245 precision of proportion is 0.001. The proportion of distribution will be
246 rounded to 3 decimal places.
247 Currently, memaslap only testss set and get commands. And it
248 testss 100% set and 100% get. For 100% get, it will preset some objects to
250 .SS Multi\-thread and concurrency
252 The high performance of memaslap benefits from the special
253 schedule of thread and concurrency. It’s important to specify the proper
254 number of them. The default number of threads is 1; the default number of
255 concurrency is 16. The user can use “—threads” and “\-\-concurrency” to
256 specify these variables.
258 If the system tests setting CPU affinity and the number of threads
259 specified by the user is greater than 1, memaslap will try to
260 bind each thread to a different CPU core. So if you want to get the best
261 performance memaslap, it is better to specify the number of
262 thread equal to the number of CPU cores. The number of threads specified by
263 the user can also be less or greater than the number of CPU cores. Because
264 of the limitation of implementation, the number of concurrencies could be
265 the multiple of the number of threads.
268 For 8 CPU cores system
273 \-\-threads=2 \-\-concurrency=128
275 \-\-threads=8 \-\-concurrency=128
277 \-\-threads=8 \-\-concurrency=256
279 \-\-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).
330 (1). cache miss rate 0%
334 (2). cache miss rate 5%
342 (1). cache miss rate 0%
352 The formula for calculating window size for cache miss rate 0%:
354 cache_size / concurrency / (key_size + value_size) * 0.5
356 The formula for calculating window size for cache miss rate 5%:
358 cache_size / concurrency / (key_size + value_size) * 0.7
361 Memslap testss both data verification and expire\-time
362 verification. The user can use "\-\-verify=" or "\-v" to specify the proportion
363 of data verification. In theory, it testss 100% data verification. The
364 user can use "\-\-exp_verify=" or "\-e" to specify the proportion of
365 expire\-time verification. In theory, it testss 100% expire\-time
366 verification. Specify the "\-\-verbose" options to get more detailed error
369 For example: \-\-exp_verify=0.01 –verify=0.1 , it means that 1% of the objects
370 set with expire\-time, 10% of the objects gotten will be verified. If the
371 objects are gotten, memaslap will verify the expire\-time and
373 .SS multi\-servers and multi\-config
375 Memslap testss multi\-servers based on self\-governed thread.
376 There is a limitation that the number of servers cannot be greater than the
377 number of threads. Memslap assigns one thread to handle one
378 server at least. The user can use the "\-\-servers=" or "\-s" option to specify
383 \-\-servers=10.1.1.1:11211,10.1.1.2:11212,10.1.1.3:11213 \-\-threads=6 \-\-concurrency=36
385 The above command means that there are 6 threads, with each thread having 6
386 concurrencies and that threads 0 and 3 handle server 0 (10.1.1.1); threads 1
387 and 4 handle server 1 (10.1.1.2); and thread 2 and 5 handle server 2
390 All the threads and concurrencies in memaslap are self\-governed.
392 So is memaslap. The user can start up several
393 memaslap instances. The user can run memaslap on different client
394 machines to communicate with the same memcached server at the same. It is
395 recommended that the user start different memaslap on different
396 machines using the same configuration.
397 .SS Run with execute number mode or time mode
399 The default memaslap runs with time mode. The default run time
400 is 10 minutes. If it times out, memaslap will exit. Do not
401 specify both execute number mode and time mode at the same time; just
406 \-\-time=30s (It means the test will run 30 seconds.)
408 \-\-execute_number=100000 (It means that after running 100000 commands, the test will exit.)
409 .SS Dump statistic information periodically.
411 The user can use "\-\-stat_freq=" or "\-S" to specify the frequency.
417 Memslap will dump the statistics of the commands (get and set) at the frequency of every 20
420 For more information on the format of dumping statistic information, refer to “Format of Output” section.
423 The user can use "\-\-division=" or "\-d" to specify multi\-get keys count.
424 Memslap by default does single get with TCP. Memslap also testss data
425 verification and expire\-time verification for multi\-get.
427 Memslap testss multi\-get with both TCP and UDP. Because of
428 the different implementation of the ASCII protocol and binary protocol,
429 there are some differences between the two. For the ASCII protocol,
430 memaslap sends one “multi\-get” to the server once. For the
431 binary protocol, memaslap sends several single get commands
432 together as “multi\-get” to the server.
435 Memslap testss both UDP and TCP. For TCP,
436 memaslap does not reconnect the memcached server if socket connections are
437 lost. If all the socket connections are lost or memcached server crashes,
438 memaslap will exit. If the user specifies the “\-\-reconnect”
439 option when socket connections are lost, it will reconnect them.
441 User can use “\-\-udp” to enable the UDP feature, but UDP comes with some
444 UDP cannot set data more than 1400 bytes.
446 UDP is not testsed by the binary protocol because the binary protocol of
447 memcached does not tests that.
449 UDP doesn’t tests reconnection.
452 Set data with TCP and multi\-get with UDP. Specify the following options:
454 "\-\-facebook \-\-division=50"
456 If you want to create thousands of TCP connections, specify the
458 "\-\-conn_sock=" option.
460 For example: \-\-facebook \-\-division=50 \-\-conn_sock=200
462 The above command means that memaslap will do facebook test,
463 each concurrency has 200 socket TCP connections and one UDP socket.
465 Memslap sets objects with the TCP socket, and multi\-gets 50
466 objects once with the UDP socket.
468 If you specify "\-\-division=50", the key size must be less that 25 bytes
469 because the UDP packet size is 1400 bytes.
472 For replication test, the user must specify at least two memcached servers.
473 The user can use “—rep_write=” option to enable feature.
477 \-\-servers=10.1.1.1:11211,10.1.1.2:11212 –rep_write=2
479 The above command means that there are 2 replication memcached servers,
480 memaslap will set objects to both server 0 and server 1, get
481 objects which are set to server 0 before from server 1, and also get objects
482 which are set to server 1 before from server 0. If server 0 crashes,
483 memaslap will only get objects from server 1. If server 0 comes
484 back to life again, memaslap will reconnect server 0. If both
485 server 0 and server 1 crash, memaslap will exit.
486 .SS Supports thousands of TCP connections
488 Start memaslap with "\-\-conn_sock=" or "\-n" to enable this
489 feature. Make sure that your system can tests opening thousands of files
490 and creating thousands of sockets. However, this feature does not tests
491 reconnection if sockets disconnect.
495 \-\-threads=8 \-\-concurrency=128 \-\-conn_sock=128
497 The above command means that memaslap starts up 8 threads, each
498 thread has 16 concurrencies, each concurrency has 128 TCP socket
499 connections, and the total number of TCP socket connections is 128 * 128 =
501 .SS Supports binary protocol
503 Start memaslap with "\-\-binary" or "\-B" options to enable this
504 feature. It testss all the above features except UDP, because the latest
505 memcached 1.3.3 does not implement binary UDP protocol.
511 Since memcached 1.3.3 doesn\(aqt implement binary UDP protocol,
512 memaslap does not tests UDP. In addition, memcached 1.3.3 does not tests
513 multi\-get. If you specify "\-\-division=50" option, it just sends 50 get
514 commands together as “mulit\-get” to the server.
515 .SH CONFIGURATION FILE
517 This section describes the format of the configuration file. By default
518 when no configuration file is specified memaslap reads the default
519 one located at ~/.memaslap.cnf.
521 Below is a sample configuration file:
525 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
526 #comments should start with \(aq#\(aq
528 #start_len end_len proportion
530 #key length range from start_len to end_len
531 #start_len must be equal to or greater than 16
532 #end_len must be equal to or less than 250
533 #start_len must be equal to or greater than end_len
534 #memaslap will generate keys according to the key range
535 #proportion: indicates keys generated from one range accounts for the total
538 #example1: key range 16~100 accounts for 80%
539 # key range 101~200 accounts for 10%
540 # key range 201~250 accounts for 10%
541 # total should be 1 (0.8+0.1+0.1 = 1)
547 #example2: all keys length are 128 bytes
553 #start_len end_len proportion
555 #value length range from start_len to end_len
556 #start_len must be equal to or greater than 1
557 #end_len must be equal to or less than 1M
558 #start_len must be equal to or greater than end_len
559 #memaslap will generate values according to the value range
560 #proportion: indicates values generated from one range accounts for the
561 total generated values
563 #example1: value range 1~1000 accounts for 80%
564 # value range 1001~10000 accounts for 10%
565 # value range 10001~100000 accounts for 10%
566 # total should be 1 (0.8+0.1+0.1 = 1)
572 #example2: all value length are 128 bytes
578 #cmd_type cmd_proportion
580 #currently memaslap only testss get and set command.
586 #example: set command accounts for 50%
587 # get command accounts for 50%
588 # total should be 1 (0.5+0.5 = 1)
600 At the beginning, memaslap displays some configuration information as follows:
602 servers : 127.0.0.1:11211
612 set proportion: set_prop=0.10
614 get proportion: get_prop=0.90
620 The servers used by memaslap.
627 The number of threads memaslap runs with.
634 The number of concurrencies memaslap runs with.
641 How long to run memaslap.
648 The task window size of each concurrency.
655 The proportion of set command.
662 The proportion of get command.
666 The output of dynamic statistics is something like this:
670 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
672 Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us)
673 Avg(us) Std_dev Geo_dist
674 Period 5 345826 69165 65.3 0 27 2198 203
676 Global 20 1257935 62896 71.8 0 26 3791 224
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 38425 7685 7.3 0 42 628 240
685 Global 20 139780 6989 8.0 0 37 3790 253
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 384252 76850 72.5 0 27 2198 207
694 Global 20 1397720 69886 79.7 0 26 3791 227
696 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
704 Statistics information of get command
711 Statistics information of set command
718 Statistics information of both get and set command
725 Result within a period
746 Throughput, operations/second
760 How many objects can’t be gotten
767 The minimum response time
774 The maximum response time
781 The average response time
788 Standard deviation of response time
795 Geometric distribution based on natural exponential function
799 At the end, memaslap will output something like this:
803 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
804 Get Statistics (1257956 events)
812 8: 484890 459823 12543 824
815 Set Statistics (139782 events)
823 8: 50784 65574 2064 167
826 Total Statistics (1397738 events)
834 8: 535674 525397 14607 991
844 written_bytes: 242516030
845 read_bytes: 1003702556
846 object_bytes: 152086080
851 Run time: 20.0s Ops: 1397754 TPS: 69817 Net_rate: 59.4M/s
852 \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
860 Get statistics of response time
867 Set statistics of response time
874 Both get and set statistics of response time
881 The accumulated and minimum response time
888 The accumulated and maximum response time
895 The accumulated and average response time
902 Standard deviation of response time
909 Geometric distribution based on logarithm 2
916 Total get commands done
923 Total set commands done
930 How many objects can’t be gotten from server
937 How many objects need to verify but can’t get them
944 How many objects with insistent value
951 How many objects are expired but we get them
958 How many objects are unexpired but we can’t get them
986 How many UDP packages are disorder
993 How many UDP packages are lost
1000 How many times UDP time out happen
1021 Throughput, operations/second
1028 The average rate of network
1034 .B \-s, \-\-servers=
1035 List one or more servers to connect. Servers count must be less than
1036 threads count. e.g.: \-\-servers=localhost:1234,localhost:11211
1038 .B \-T, \-\-threads=
1039 Number of threads to startup, better equal to CPU numbers. Default 8.
1041 .B \-c, \-\-concurrency=
1042 Number of concurrency to simulate with load. Default 128.
1044 .B \-n, \-\-conn_sock=
1045 Number of TCP socks per concurrency. Default 1.
1047 .B \-x, \-\-execute_number=
1048 Number of operations(get and set) to execute for the
1049 given test. Default 1000000.
1052 How long the test to run, suffix: s\-seconds, m\-minutes, h\-hours,
1053 d\-days e.g.: \-\-time=2h.
1055 .B \-F, \-\-cfg_cmd=
1056 Load the configure file to get command,key and value distribution list.
1058 .B \-w, \-\-win_size=
1059 Task window size of each concurrency, suffix: K, M e.g.: \-\-win_size=10k.
1062 .B \-X, \-\-fixed_size=
1063 Fixed length of value.
1066 The proportion of date verification, e.g.: \-\-verify=0.01
1068 .B \-d, \-\-division=
1069 Number of keys to multi\-get once. Default 1, means single get.
1071 .B \-S, \-\-stat_freq=
1072 Frequency of dumping statistic information. suffix: s\-seconds,
1073 m\-minutes, e.g.: \-\-resp_freq=10s.
1075 .B \-e, \-\-exp_verify=
1076 The proportion of objects with expire time, e.g.: \-\-exp_verify=0.01.
1077 Default no object with expire time
1079 .B \-o, \-\-overwrite=
1080 The proportion of objects need overwrite, e.g.: \-\-overwrite=0.01.
1081 Default never overwrite object.
1085 .B \-R, \-\-reconnect
1086 Reconnect tests, when connection is closed it will be reconnected.
1089 UDP tests, default memaslap uses TCP, TCP port and UDP port of
1090 server must be same.
1092 .B \-a, \-\-facebook
1093 Whether it enables facebook test feature, set with TCP and multi\-get with UDP.
1096 Whether it enables binary protocol. Default with ASCII protocol.
1101 Expected throughput, suffix: K, e.g.: \-\-tps=10k.
1103 .B \-p, \-\-rep_write=
1104 The first nth servers can write data, e.g.: \-\-rep_write=2.
1109 Whether it outputs detailed information when verification fails.
1112 Display this message and then exit.
1115 Display the version of the application and then exit.
1119 memaslap \-s 127.0.0.1:11211 \-S 5s
1121 memaslap \-s 127.0.0.1:11211 \-t 2m \-v 0.2 \-e 0.05 \-b
1123 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-w 40k \-S 20s \-o 0.2
1125 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-T 4 \-c 128 \-d 20 \-P 40k
1127 memaslap \-s 127.0.0.1:11211 \-F config \-t 2m \-d 50 \-a \-n 40
1129 memaslap \-s 127.0.0.1:11211,127.0.0.1:11212 \-F config \-t 2m
1131 memaslap \-s 127.0.0.1:11211,127.0.0.1:11212 \-F config \-t 2m \-p 2
1134 To find out more information please check:
1135 \fI\%http://libmemcached.org/\fP
1138 Mingqiang Zhuang <\fI\%mingqiangzhuang@hengtiansoft.com\fP> (Schooner Technolgy)
1139 Brian Aker, <\fI\%brian@tangent.org\fP>
1142 \fImemcached(1)\fP \fIlibmemcached(3)\fP
1146 2011, Brian Aker DataDifferential, http://datadifferential.com/
1147 .\" Generated by docutils manpage writer.