1MEMASLAP(1) libmemcached MEMASLAP(1)
2
6 memaslap - libmemcached Documentation
7
9 memaslap [options]
10 --help
12 MEMCACHED_SERVERS
14
16 memaslap is a load generation and benchmark tool for memcached servers.
17 It generates configurable workload such as threads, concurrencies, con‐
18 nections, run time, overwrite, miss rate, key size, value size, get/set
19 proportion, expected throughput, and so on. Furthermore, it also testss
20 data verification, expire-time verification, UDP, binary protocol,
21 facebook test, replication test, multi-get and reconnection, etc.
22 Memaslap manages network connections like memcached with libevent. Each
24 thread of memaslap is bound with a CPU core, all the threads don't com‐
25 municate with each other, and there are several socket connections in
26 each thread. Each connection keeps key size distribution, value size
27 distribution, and command distribution by itself.
28 You can specify servers via the memslap --servers option or via the
30 environment variable MEMCACHED_SERVERS.
31
33 Memslap is developed to for the following purposes:
34 Manages network connections with libevent asynchronously.
36 Set both TCP and UDP up to use non-blocking IO.
38 Improves parallelism: higher performance in multi-threads environments.
40 Improves time efficiency: faster processing speed.
42 Generates key and value more efficiently; key size distribution and
44 value size distribution are configurable.
45 Supports get, multi-get, and set commands; command distribution is con‐
47 figurable.
48 Supports controllable miss rate and overwrite rate.
50 Supports data and expire-time verification.
52 Supports dumping statistic information periodically.
54 Supports thousands of TCP connections.
56 Supports binary protocol.
58 Supports facebook test (set with TCP and multi-get with UDP) and repli‐
60 cation test.
61
63 Effective implementation of network.
64 For memaslap, both TCP and UDP use non-blocking network IO. All the
65 network events are managed by libevent as memcached. The network module
66 of memaslap is similar to memcached. Libevent can ensure memaslap can
67 handle network very efficiently.
68 Effective implementation of multi-threads and concurrency
70 Memslap has the similar implementation of multi-threads to memcached.
71 Memslap creates one or more self-governed threads; each thread is bound
72 with one CPU core if the system testss setting CPU core affinity.
73 In addition, each thread has a libevent to manage the events of the
75 network; each thread has one or more self-governed concurrencies; and
76 each concurrency has one or more socket connections. All the concurren‐
77 cies don’t communicate with each other even though they are in the same
78 thread.
79 Memslap can create thousands of socket connections, and each concur‐
81 rency has tens of socket connections. Each concurrency randomly or
82 sequentially selects one socket connection from its socket connection
83 pool to run, so memaslap can ensure each concurrency handles one socket
84 connection at any given time. Users can specify the number of concur‐
85 rency and socket connections of each concurrency according to their
86 expected workload.
87 Effective implementation of generating key and value
89 In order to improve time efficiency and space efficiency, memaslap cre‐
90 ates a random characters table with 10M characters. All the suffixes of
91 keys and values are generated from this random characters table.
92 Memslap uses the offset in the character table and the length of the
94 string to identify a string. It can save much memory. Each key con‐
95 tains two parts, a prefix and a suffix. The prefix is an uint64_t, 8
96 bytes. In order to verify the data set before, memaslap need to ensure
97 each key is unique, so it uses the prefix to identify a key. The prefix
98 cannot include illegal characters, such as ‘r’, ‘n’, ‘0’ and ‘ ‘. And
99 memaslap has an algorithm to ensure that.
100 Memslap doesn’t generate all the objects (key-value pairs) at the
102 beginning. It only generates enough objects to fill the task window
103 (default 10K objects) of each concurrency. Each object has the follow‐
104 ing basic information, key prefix, key suffix offset in the character
105 table, key length, value offset in the character table, and value
106 length.
107 In the work process, each concurrency sequentially or randomly selects
109 an object from the window to do set operation or get operation. At the
110 same time, each concurrency kicks objects out of its window and adds
111 new object into it.
112 Simple but useful task scheduling
114 Memslap uses libevent to schedule all the concurrencies of threads, and
115 each concurrency schedules tasks based on the local task window. Mem‐
116 slap assumes that if each concurrency keeps the same key distribution,
117 value distribution and commands distribution, from outside, memaslap
118 keeps all the distribution as a whole. Each task window includes a lot
119 of objects, each object stores its basic information, such as key,
120 value, expire time, and so on. At any time, all the objects in the win‐
121 dow keep the same and fixed key and value distribution. If an object is
122 overwritten, the value of the object will be updated. Memslap verifies
123 the data or expire-time according to the object information stored in
124 the task window.
125 Libevent selects which concurrency to handle based on a specific net‐
127 work event. Then the concurrency selects which command (get or set) to
128 operate based on the command distribution. If it needs to kick out an
129 old object and add a new object, in order to keep the same key and
130 value distribution, the new object must have the same key length and
131 value length.
132 If memcached server has two cache layers (memory and SSD), running
134 memaslap with different window sizes can get different cache miss
135 rates. If memaslap adds enough objects into the windows at the begin‐
136 ning, and the cache of memcached cannot store all the objects initial‐
137 ized, then memaslap will get some objects from the second cache layer.
138 It causes the first cache layer to miss. So the user can specify the
139 window size to get the expected miss rate of the first cache layer.
140 Useful implementation of multi-servers , UDP, TCP, multi-get and binary
142 protocol
143 Because each thread is self-governed, memaslap can assign different
144 threads to handle different memcached servers. This is just one of the
145 ways in which memaslap tests multiple servers. The only limitation is
146 that the number of servers cannot be greater than the number of
147 threads. The other way to test multiple servers is for replication
148 test. Each concurrency has one socket connection to each memcached
149 server. For the implementation, memaslap can set some objects to one
150 memcached server, and get these objects from the other servers.
151 By default, Memslap does single get. If the user specifies multi-get
153 option, memaslap will collect enough get commands and pack and send the
154 commands together.
155 Memslap testss both the ASCII protocol and binary protocol, but it runs
157 on the ASCII protocol by default. Memslap by default runs on the TCP
158 protocol, but it also tests UDP. Because UDP is unreliable, dropped
159 packages and out-of-order packages may occur. Memslap creates a memory
160 buffer to handle these problems. Memslap tries to read all the response
161 data of one command from the server and reorders the response data. If
162 some packages get lost, the waiting timeout mechanism can ensure
163 half-baked packages will be discarded and the next command will be
164 sent.
165
167 Below are some usage samples:
168 memaslap -s 127.0.0.1:11211 -S 5s
170 memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b
172 memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2
174 memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k
176 memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40
178 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m
180 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2
182 The user must specify one server at least to run memaslap. The rest of
184 the parameters have default values, as shown below:
185 Thread number = 1 Concurrency = 16
187 Run time = 600 seconds Configuration file = NULL
189 Key size = 64 Value size = 1024
191 Get/set = 9:1 Window size = 10k
193 Execute number = 0 Single get = true
195 Multi-get = false Number of sockets of each con‐
197 currency = 1
198 Reconnect = false Data verification = false
200 Expire-time verification = false ASCII protocol = true
202 Binary protocol = false Dumping statistic information
204 periodically = false
206 Overwrite proportion = 0% UDP = false
208 TCP = true Limit throughput = false
210 Facebook test = false Replication test = false
212 Key size, value size and command distribution.
214 All the distributions are read from the configuration file specified by
215 user with “—cfg_cmd” option. If the user does not specify a configura‐
216 tion file, memaslap will run with the default distribution (key size =
217 64, value size = 1024, get/set = 9:1). For information on how to edit
218 the configuration file, refer to the “Configuration File” section.
219 The minimum key size is 16 bytes; the maximum key size is 250 bytes.
221 The precision of proportion is 0.001. The proportion of distribution
222 will be rounded to 3 decimal places.
223 The minimum value size is 1 bytes; the maximum value size is 1M bytes.
225 The precision of proportion is 0.001. The proportion of distribution
226 will be rounded to 3 decimal places. Currently, memaslap only testss
227 set and get commands. And it testss 100% set and 100% get. For 100%
228 get, it will preset some objects to the server.
229 Multi-thread and concurrency
231 The high performance of memaslap benefits from the special schedule of
232 thread and concurrency. It’s important to specify the proper number of
233 them. The default number of threads is 1; the default number of concur‐
234 rency is 16. The user can use “—threads” and “--concurrency” to specify
235 these variables.
236 If the system tests setting CPU affinity and the number of threads
238 specified by the user is greater than 1, memaslap will try to bind each
239 thread to a different CPU core. So if you want to get the best perfor‐
240 mance memaslap, it is better to specify the number of thread equal to
241 the number of CPU cores. The number of threads specified by the user
242 can also be less or greater than the number of CPU cores. Because of
243 the limitation of implementation, the number of concurrencies could be
244 the multiple of the number of threads.
245 1. For 8 CPU cores system
247 For example:
249 --threads=2 --concurrency=128
251 --threads=8 --concurrency=128
253 --threads=8 --concurrency=256
255 --threads=12 --concurrency=144
257 2. For 16 CPU cores system
259 For example:
261 --threads=8 --concurrency=128
263 --threads=16 --concurrency=256
265 --threads=16 --concurrency=512
267 --threads=24 --concurrency=288
269 The memaslap performs very well, when used to test the performance of
271 memcached servers. Most of the time, the bottleneck is the network or
272 the server. If for some reason the user wants to limit the performance
273 of memaslap, there are two ways to do this:
274 Decrease the number of threads and concurrencies. Use the option
276 “--tps” that memaslap provides to limit the throughput. This option
277 allows the user to get the expected throughput. For example, assume
278 that the maximum throughput is 50 kops/s for a specific configuration,
279 you can specify the throughput equal to or less than the maximum
280 throughput using “--tps” option.
281 Window size
283 Most of the time, the user does not need to specify the window size.
284 The default window size is 10k. For Schooner Memcached, the user can
285 specify different window sizes to get different cache miss rates based
286 on the test case. Memslap testss cache miss rate between 0% and 100%.
287 If you use this utility to test the performance of Schooner Memcached,
288 you can specify a proper window size to get the expected cache miss
289 rate. The formula for calculating window size is as follows:
290 Assume that the key size is 128 bytes, and the value size is 2048
292 bytes, and concurrency=128.
293 1. Small cache cache_size=1M, 100% cache miss (all data get from SSD).
295 win_size=10k
296 2. cache_size=4G
298 (1). cache miss rate 0%
300 win_size=8k
302 (2). cache miss rate 5%
304 win_size=11k
306 3. cache_size=16G
308 (1). cache miss rate 0%
310 win_size=32k
312 (2). cache miss
314 rate 5%
316 win_size=46k
318 The formula for calculating window size for cache miss rate 0%:
320 cache_size / concurrency / (key_size + value_size) * 0.5
322 The formula for calculating window size for cache miss rate 5%:
324 cache_size / concurrency / (key_size + value_size) * 0.7
326 Verification
328 Memslap testss both data verification and expire-time verification. The
329 user can use "--verify=" or "-v" to specify the proportion of data ver‐
330 ification. In theory, it testss 100% data verification. The user can
331 use "--exp_verify=" or "-e" to specify the proportion of expire-time
332 verification. In theory, it testss 100% expire-time verification. Spec‐
333 ify the "--verbose" options to get more detailed error information.
334 For example: --exp_verify=0.01 –verify=0.1 , it means that 1% of the
336 objects set with expire-time, 10% of the objects gotten will be veri‐
337 fied. If the objects are gotten, memaslap will verify the expire-time
338 and value.
339 multi-servers and multi-config
341 Memslap testss multi-servers based on self-governed thread. There is a
342 limitation that the number of servers cannot be greater than the number
343 of threads. Memslap assigns one thread to handle one server at least.
344 The user can use the "--servers=" or "-s" option to specify
345 multi-servers.
346 For example:
348 --servers=10.1.1.1:11211,10.1.1.2:11212,10.1.1.3:11213 --threads=6
350 --concurrency=36
351 The above command means that there are 6 threads, with each thread hav‐
353 ing 6 concurrencies and that threads 0 and 3 handle server 0
354 (10.1.1.1); threads 1 and 4 handle server 1 (10.1.1.2); and thread 2
355 and 5 handle server 2 (10.1.1.3).
356 All the threads and concurrencies in memaslap are self-governed.
358 So is memaslap. The user can start up several memaslap instances. The
360 user can run memaslap on different client machines to communicate with
361 the same memcached server at the same. It is recommended that the user
362 start different memaslap on different machines using the same configu‐
363 ration.
364 Run with execute number mode or time mode
366 The default memaslap runs with time mode. The default run time is 10
367 minutes. If it times out, memaslap will exit. Do not specify both exe‐
368 cute number mode and time mode at the same time; just specify one
369 instead.
370 For example:
372 --time=30s (It means the test will run 30 seconds.)
374 --execute_number=100000 (It means that after running 100000 commands,
376 the test will exit.)
377 Dump statistic information periodically.
379 The user can use "--stat_freq=" or "-S" to specify the frequency.
380 For example:
382 --stat_freq=20s
384 Memslap will dump the statistics of the commands (get and set) at the
386 frequency of every 20 seconds.
387 For more information on the format of dumping statistic information,
389 refer to “Format of Output” section.
390 Multi-get
392 The user can use "--division=" or "-d" to specify multi-get keys count.
393 Memslap by default does single get with TCP. Memslap also testss data
394 verification and expire-time verification for multi-get.
395 Memslap testss multi-get with both TCP and UDP. Because of the differ‐
397 ent implementation of the ASCII protocol and binary protocol, there are
398 some differences between the two. For the ASCII protocol, memaslap
399 sends one “multi-get” to the server once. For the binary protocol,
400 memaslap sends several single get commands together as “multi-get” to
401 the server.
402 UDP and TCP
404 Memslap testss both UDP and TCP. For TCP, memaslap does not reconnect
405 the memcached server if socket connections are lost. If all the socket
406 connections are lost or memcached server crashes, memaslap will exit.
407 If the user specifies the “--reconnect” option when socket connections
408 are lost, it will reconnect them.
409 User can use “--udp” to enable the UDP feature, but UDP comes with some
411 limitations:
412 UDP cannot set data more than 1400 bytes.
414 UDP is not testsed by the binary protocol because the binary protocol
416 of memcached does not tests that.
417 UDP doesn’t tests reconnection.
419 Facebook test
421 Set data with TCP and multi-get with UDP. Specify the following
422 options:
423 "--facebook --division=50"
425 If you want to create thousands of TCP connections, specify the
427 "--conn_sock=" option.
429 For example: --facebook --division=50 --conn_sock=200
431 The above command means that memaslap will do facebook test, each con‐
433 currency has 200 socket TCP connections and one UDP socket.
434 Memslap sets objects with the TCP socket, and multi-gets 50 objects
436 once with the UDP socket.
437 If you specify "--division=50", the key size must be less that 25 bytes
439 because the UDP packet size is 1400 bytes.
440 Replication test
442 For replication test, the user must specify at least two memcached
443 servers. The user can use “—rep_write=” option to enable feature.
444 For example:
446 --servers=10.1.1.1:11211,10.1.1.2:11212 –rep_write=2
448 The above command means that there are 2 replication memcached servers,
450 memaslap will set objects to both server 0 and server 1, get objects
451 which are set to server 0 before from server 1, and also get objects
452 which are set to server 1 before from server 0. If server 0 crashes,
453 memaslap will only get objects from server 1. If server 0 comes back to
454 life again, memaslap will reconnect server 0. If both server 0 and
455 server 1 crash, memaslap will exit.
456 Supports thousands of TCP connections
458 Start memaslap with "--conn_sock=" or "-n" to enable this feature. Make
459 sure that your system can tests opening thousands of files and creating
460 thousands of sockets. However, this feature does not tests reconnection
461 if sockets disconnect.
462 For example:
464 --threads=8 --concurrency=128 --conn_sock=128
466 The above command means that memaslap starts up 8 threads, each thread
468 has 16 concurrencies, each concurrency has 128 TCP socket connections,
469 and the total number of TCP socket connections is 128 * 128 = 16384.
470 Supports binary protocol
472 Start memaslap with "--binary" or "-B" options to enable this feature.
473 It testss all the above features except UDP, because the latest mem‐
474 cached 1.3.3 does not implement binary UDP protocol.
475 For example:
477 --binary
479 Since memcached 1.3.3 doesn't implement binary UDP protocol, memaslap
481 does not tests UDP. In addition, memcached 1.3.3 does not tests
482 multi-get. If you specify "--division=50" option, it just sends 50 get
483 commands together as “mulit-get” to the server.
484
486 This section describes the format of the configuration file. By
487 default when no configuration file is specified memaslap reads the
488 default one located at ~/.memaslap.cnf.
489 Below is a sample configuration file:
491 ---------------------------------------------------------------------------
493 #comments should start with '#'
494 #key
495 #start_len end_len proportion
496 #
497 #key length range from start_len to end_len
498 #start_len must be equal to or greater than 16
499 #end_len must be equal to or less than 250
500 #start_len must be equal to or greater than end_len
501 #memaslap will generate keys according to the key range
502 #proportion: indicates keys generated from one range accounts for the total
503 generated keys
504 #
505 #example1: key range 16~100 accounts for 80%
506 # key range 101~200 accounts for 10%
507 # key range 201~250 accounts for 10%
508 # total should be 1 (0.8+0.1+0.1 = 1)
509 #
510 # 16 100 0.8
511 # 101 200 0.1
512 # 201 249 0.1
513 #
514 #example2: all keys length are 128 bytes
515 #
516 # 128 128 1
517 key
518 128 128 1
519 #value
520 #start_len end_len proportion
521 #
522 #value length range from start_len to end_len
523 #start_len must be equal to or greater than 1
524 #end_len must be equal to or less than 1M
525 #start_len must be equal to or greater than end_len
526 #memaslap will generate values according to the value range
527 #proportion: indicates values generated from one range accounts for the
528 total generated values
529 #
530 #example1: value range 1~1000 accounts for 80%
531 # value range 1001~10000 accounts for 10%
532 # value range 10001~100000 accounts for 10%
533 # total should be 1 (0.8+0.1+0.1 = 1)
534 #
535 # 1 1000 0.8
536 # 1001 10000 0.1
537 # 10001 100000 0.1
538 #
539 #example2: all value length are 128 bytes
540 #
541 # 128 128 1
542 value
543 2048 2048 1
544 #cmd
545 #cmd_type cmd_proportion
546 #
547 #currently memaslap only testss get and set command.
548 #
549 #cmd_type
550 #set 0
551 #get 1
552 #
553 #example: set command accounts for 50%
554 # get command accounts for 50%
555 # total should be 1 (0.5+0.5 = 1)
556 #
557 # cmd
558 # 0 0.5
559 # 1 0.5
560 cmd
561 0 0.1
562 1.0 0.9
563
565 At the beginning, memaslap displays some configuration information as
566 follows:
567 servers : 127.0.0.1:11211
569 threads count: 1
571 concurrency: 16
573 run time: 20s
575 windows size: 10k
577 set proportion: set_prop=0.10
579 get proportion: get_prop=0.90
581 Where
583 servers : "servers"
584 The servers used by memaslap.
585 threads count
587 The number of threads memaslap runs with.
588 concurrency
590 The number of concurrencies memaslap runs with.
591 run time
593 How long to run memaslap.
594 windows size
596 The task window size of each concurrency.
597 set proportion
599 The proportion of set command.
600 get proportion
602 The proportion of get command.
603 The output of dynamic statistics is something like this:
605 ---------------------------------------------------------------------------------------------------------------------------------
607 Get Statistics
608 Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us)
609 Avg(us) Std_dev Geo_dist
610 Period 5 345826 69165 65.3 0 27 2198 203
611 95.43 177.29
612 Global 20 1257935 62896 71.8 0 26 3791 224
613 117.79 192.60
614 Set Statistics
617 Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us)
618 Avg(us) Std_dev Geo_dist
619 Period 5 38425 7685 7.3 0 42 628 240
620 88.05 220.21
621 Global 20 139780 6989 8.0 0 37 3790 253
622 117.93 224.83
623 Total Statistics
626 Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us)
627 Avg(us) Std_dev Geo_dist
628 Period 5 384252 76850 72.5 0 27 2198 207
629 94.72 181.18
630 Global 20 1397720 69886 79.7 0 26 3791 227
631 117.93 195.60
632 ---------------------------------------------------------------------------------------------------------------------------------
633 Where
635 Get Statistics
636 Statistics information of get command
637 Set Statistics
639 Statistics information of set command
640 Total Statistics
642 Statistics information of both get and set command
643 Period
645 Result within a period
646 Global
648 Accumulated results
649 Ops
651 Total operations
652 TPS
654 Throughput, operations/second
655 Net
657 The rate of network
658 Get_miss
660 How many objects can’t be gotten
661 Min
663 The minimum response time
664 Max
666 The maximum response time
667 Avg:
669 The average response time
670 Std_dev
672 Standard deviation of response time
673 Geo_dist
675 Geometric distribution based on natural exponential function
676 At the end, memaslap will output something like this:
678 ---------------------------------------------------------------------------------------------------------------------------------
680 Get Statistics (1257956 events)
681 Min: 26
682 Max: 3791
683 Avg: 224
684 Geo: 192.60
685 Std: 116.23
686 Log2 Dist:
687 4: 0 10 84490 215345
688 8: 484890 459823 12543 824
689 12: 31
690 Set Statistics (139782 events)
692 Min: 37
693 Max: 3790
694 Avg: 253
695 Geo: 224.84
696 Std: 116.83
697 Log2 Dist:
698 4: 0 0 4200 16988
699 8: 50784 65574 2064 167
700 12: 5
701 Total Statistics (1397738 events)
703 Min: 26
704 Max: 3791
705 Avg: 227
706 Geo: 195.60
707 Std: 116.60
708 Log2 Dist:
709 4: 0 10 88690 232333
710 8: 535674 525397 14607 991
711 12: 36
712 cmd_get: 1257969
714 cmd_set: 139785
715 get_misses: 0
716 verify_misses: 0
717 verify_failed: 0
718 expired_get: 0
719 unexpired_unget: 0
720 written_bytes: 242516030
721 read_bytes: 1003702556
722 object_bytes: 152086080
723 packet_disorder: 0
724 packet_drop: 0
725 udp_timeout: 0
726 Run time: 20.0s Ops: 1397754 TPS: 69817 Net_rate: 59.4M/s
728 ---------------------------------------------------------------------------------------------------------------------------------
729 Where
731 Get Statistics
732 Get statistics of response time
733 Set Statistics
735 Set statistics of response time
736 Total Statistics
738 Both get and set statistics of response time
739 Min
741 The accumulated and minimum response time
742 Max
744 The accumulated and maximum response time
745 Avg
747 The accumulated and average response time
748 Std
750 Standard deviation of response time
751 Log2 Dist
753 Geometric distribution based on logarithm 2
754 cmd_get
756 Total get commands done
757 cmd_set
759 Total set commands done
760 get_misses
762 How many objects can’t be gotten from server
763 verify_misses
765 How many objects need to verify but can’t get them
766 verify_failed
768 How many objects with insistent value
769 expired_get
771 How many objects are expired but we get them
772 unexpired_unget
774 How many objects are unexpired but we can’t get them
775 written_bytes
777 Total written bytes
778 read_bytes
780 Total read bytes
781 object_bytes
783 Total object bytes
784 packet_disorder
786 How many UDP packages are disorder
787 packet_drop
789 How many UDP packages are lost
790 udp_timeout
792 How many times UDP time out happen
793 Run time
795 Total run time
796 Ops
798 Total operations
799 TPS
801 Throughput, operations/second
802 Net_rate
804 The average rate of network
805
807 -s, --servers=
808 List one or more servers to connect. Servers count must be less
809 than threads count. e.g.: --servers=localhost:1234,local‐
810 host:11211
811 -T, --threads=
813 Number of threads to startup, better equal to CPU numbers.
814 Default 8.
815 -c, --concurrency=
817 Number of concurrency to simulate with load. Default 128.
818 -n, --conn_sock=
820 Number of TCP socks per concurrency. Default 1.
821 -x, --execute_number=
823 Number of operations(get and set) to execute for the given test.
824 Default 1000000.
825 -t, --time=
827 How long the test to run, suffix: s-seconds, m-minutes, h-hours,
828 d-days e.g.: --time=2h.
829 -F, --cfg_cmd=
831 Load the configure file to get command,key and value distribu‐
832 tion list.
833 -w, --win_size=
835 Task window size of each concurrency, suffix: K, M e.g.:
836 --win_size=10k. Default 10k.
837 -X, --fixed_size=
839 Fixed length of value.
840 -v, --verify=
842 The proportion of date verification, e.g.: --verify=0.01
843 -d, --division=
845 Number of keys to multi-get once. Default 1, means single get.
846 -S, --stat_freq=
848 Frequency of dumping statistic information. suffix: s-seconds,
849 m-minutes, e.g.: --resp_freq=10s.
850 -e, --exp_verify=
852 The proportion of objects with expire time, e.g.: --exp_ver‐
853 ify=0.01. Default no object with expire time
854 -o, --overwrite=
856 The proportion of objects need overwrite, e.g.: --over‐
857 write=0.01. Default never overwrite object.
858 -R, --reconnect
860 Reconnect tests, when connection is closed it will be recon‐
861 nected.
862 -U, --udp
864 UDP tests, default memaslap uses TCP, TCP port and UDP port of
865 server must be same.
866 -a, --facebook
868 Whether it enables facebook test feature, set with TCP and
869 multi-get with UDP.
870 -B, --binary
872 Whether it enables binary protocol. Default with ASCII protocol.
873 -P, --tps=
875 Expected throughput, suffix: K, e.g.: --tps=10k.
876 -p, --rep_write=
878 The first nth servers can write data, e.g.: --rep_write=2.
879 -b, --verbose
881 Whether it outputs detailed information when verification fails.
882 -h, --help
884 Display this message and then exit.
885 -V, --version
887 Display the version of the application and then exit.
888
890 memaslap -s 127.0.0.1:11211 -S 5s
891 memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b
893 memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2
895 memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k
897 memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40
899 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m
901 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2
903
905 To find out more information please check: http://libmemcached.org/
906
908 Mingqiang Zhuang <mingqiangzhuang@hengtiansoft.com> (Schooner Tech‐
909 nolgy) Brian Aker, <brian@tangent.org>
910
912 memcached(1) libmemcached(3)
913
915 Brian Aker
916
918 2011-2013, Brian Aker DataDifferential, http://datadifferential.com/
9191.0.16 January 31, 2013 MEMASLAP(1)