git.m6w6.name Git - awesomized/libmemcached/blob - docs/source/bin/memaslap.rst

   1 ==================================================
   2 memaslap - Load testing  and benchmarking a server
   3 ==================================================
   4
   5
   6 --------
   7 SYNOPSIS
   8 --------
   9
  10 memaslap [options]
  11
  12 .. program:: memaslap
  13
  14 .. option:: --help
  15
  16 .. envvar:: MEMCACHED_SERVERS
  17
  18 -----------
  19 DESCRIPTION
  20 -----------
  21
  22
  23 :program:`memaslap` is a load generation and benchmark tool for memcached
  24 servers. It generates configurable workload such as threads, concurrencies,
  25 connections, run time, overwrite, miss rate, key size, value size, get/set
  26 proportion, expected throughput, and so on. Furthermore, it also testss data
  27 verification, expire-time verification, UDP, binary protocol, facebook test,
  28 replication test, multi-get and reconnection, etc.
  29
  30 Memaslap manages network connections like memcached with
  31 libevent. Each thread of memaslap is bound with a CPU core, all
  32 the threads don't communicate with each other, and there are several socket
  33 connections in each thread. Each connection keeps key size distribution,
  34 value size distribution, and command distribution by itself.
  35
  36 You can specify servers via the :option:`memslap --servers` option or via the
  37 environment variable :envvar:`MEMCACHED_SERVERS`.
  38
  39
  40 --------
  41 FEATURES
  42 --------
  43
  44
  45 Memslap is developed to for the following purposes:
  46
  47
  48 Manages network connections with libevent asynchronously.
  49
  50
  51
  52 Set both TCP and UDP up to use non-blocking IO.
  53
  54
  55
  56 Improves parallelism: higher performance in multi-threads environments.
  57
  58
  59
  60 Improves time efficiency: faster processing speed.
  61
  62
  63
  64 Generates key and value more efficiently; key size distribution and value size distribution are configurable.
  65
  66
  67
  68 Supports get, multi-get, and set commands; command distribution is configurable.
  69
  70
  71
  72 Supports controllable miss rate and overwrite rate.
  73
  74
  75
  76 Supports data and expire-time verification.
  77
  78
  79
  80 Supports dumping statistic information periodically.
  81
  82
  83
  84 Supports thousands of TCP connections.
  85
  86
  87
  88 Supports binary protocol.
  89
  90
  91
  92 Supports facebook test (set with TCP and multi-get with UDP) and replication test.
  93
  94
  95
  96
  97 -------
  98 DETAILS
  99 -------
 100
 101
 102 Effective implementation of network.
 103 ____________________________________
 104
 105
 106 For memaslap, both TCP and UDP use non-blocking network IO. All
 107 the network events are managed by libevent as memcached. The network module
 108 of memaslap is similar to memcached. Libevent can ensure
 109 memaslap can handle network very efficiently.
 110
 111
 112 Effective implementation of multi-threads and concurrency
 113 _________________________________________________________
 114
 115
 116 Memslap has the similar implementation of multi-threads to
 117 memcached. Memslap creates one or more self-governed threads;
 118 each thread is bound with one CPU core if the system testss setting CPU
 119 core affinity.
 120
 121 In addition, each thread has a libevent to manage the events of the network;
 122 each thread has one or more self-governed concurrencies; and each
 123 concurrency has one or more socket connections. All the concurrencies don’t
 124 communicate with each other even though they are in the same thread.
 125
 126 Memslap can create thousands of socket connections, and each
 127 concurrency has tens of socket connections. Each concurrency randomly or
 128 sequentially selects one socket connection from its socket connection pool
 129 to run, so memaslap can ensure each concurrency handles one
 130 socket connection at any given time. Users can specify the number of
 131 concurrency and socket connections of each concurrency according to their
 132 expected workload.
 133
 134
 135 Effective implementation of generating key and value
 136 ____________________________________________________
 137
 138
 139 In order to improve time efficiency and space efficiency,
 140 memaslap creates a random characters table with 10M characters. All the
 141 suffixes of keys and values are generated from this random characters table.
 142
 143 Memslap uses the offset in the character table and the length
 144 of the string to identify a string. It can save much memory.
 145 Each key contains two parts, a prefix and a suffix. The prefix is an
 146 uint64_t, 8 bytes. In order to verify the data set before,
 147 memaslap need to ensure each key is unique, so it uses the prefix to identify
 148 a key. The prefix cannot include illegal characters, such as ‘\r’, ‘\n’,
 149 ‘\0’ and ‘ ‘. And memaslap has an algorithm to ensure that.
 150
 151 Memslap doesn’t generate all the objects (key-value pairs) at
 152 the beginning. It only generates enough objects to fill the task window
 153 (default 10K objects) of each concurrency. Each object has the following
 154 basic information, key prefix, key suffix offset in the character table, key
 155 length, value offset in the character table, and value length.
 156
 157 In the work process, each concurrency sequentially or randomly selects an
 158 object from the window to do set operation or get operation. At the same
 159 time, each concurrency kicks objects out of its window and adds new object
 160 into it.
 161
 162
 163 Simple but useful task scheduling
 164 _________________________________
 165
 166
 167 Memslap uses libevent to schedule all the concurrencies of
 168 threads, and each concurrency schedules tasks based on the local task
 169 window. Memslap assumes that if each concurrency keeps the same
 170 key distribution, value distribution and commands distribution, from
 171 outside, memaslap keeps all the distribution as a whole.
 172 Each task window includes a lot of objects, each object stores its basic
 173 information, such as key, value, expire time, and so on. At any time, all
 174 the objects in the window keep the same and fixed key and value
 175 distribution. If an object is overwritten, the value of the object will be
 176 updated. Memslap verifies the data or expire-time according to
 177 the object information stored in the task window.
 178
 179 Libevent selects which concurrency to handle based on a specific network
 180 event. Then the concurrency selects which command (get or set) to operate
 181 based on the command distribution. If it needs to kick out an old object and
 182 add a new object, in order to keep the same key and value distribution, the
 183 new object must have the same key length and value length.
 184
 185 If memcached server has two cache layers (memory and SSD), running
 186 memaslap with different window sizes can get different cache
 187 miss rates. If memaslap adds enough objects into the windows at
 188 the beginning, and the cache of memcached cannot store all the objects
 189 initialized, then memaslap will get some objects from the second
 190 cache layer. It causes the first cache layer to miss. So the user can
 191 specify the window size to get the expected miss rate of the first cache
 192 layer.
 193
 194
 195 Useful implementation of multi-servers , UDP, TCP, multi-get and binary protocol
 196 ________________________________________________________________________________
 197
 198
 199 Because each thread is self-governed, memaslap can assign
 200 different threads to handle different memcached servers. This is just one of
 201 the ways in which memaslap tests multiple servers. The only
 202 limitation is that the number of servers cannot be greater than the number
 203 of threads. The other way to test multiple servers is for replication
 204 test. Each concurrency has one socket connection to each memcached server.
 205 For the implementation, memaslap can set some objects to one
 206 memcached server, and get these objects from the other servers.
 207
 208 By default, Memslap does single get. If the user specifies
 209 multi-get option, memaslap will collect enough get commands and
 210 pack and send the commands together.
 211
 212 Memslap testss both the ASCII protocol and binary protocol,
 213 but it runs on the ASCII protocol by default.
 214 Memslap by default runs on the TCP protocol, but it also
 215 tests UDP. Because UDP is unreliable, dropped packages and out-of-order
 216 packages may occur. Memslap creates a memory buffer to handle
 217 these problems. Memslap tries to read all the response data of
 218 one command from the server and reorders the response data. If some packages
 219 get lost, the waiting timeout mechanism can ensure half-baked packages will
 220 be discarded and the next command will be sent.
 221
 222
 223
 224 -----
 225 USAGE
 226 -----
 227
 228
 229 Below are some usage samples:
 230
 231
 232 memaslap -s 127.0.0.1:11211 -S 5s
 233
 234
 235
 236 memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b
 237
 238
 239
 240 memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2
 241
 242
 243
 244 memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k
 245
 246
 247
 248 memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40
 249
 250
 251
 252 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m
 253
 254
 255
 256 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2
 257
 258
 259
 260 The user must specify one server at least to run memaslap. The
 261 rest of the parameters have default values, as shown below:
 262
 263 Thread number = 1                    Concurrency = 16
 264
 265 Run time = 600 seconds                Configuration file = NULL
 266
 267 Key size = 64                         Value size = 1024
 268
 269 Get/set = 9:1                         Window size = 10k
 270
 271 Execute number = 0                   Single get = true
 272
 273 Multi-get = false                      Number of sockets of each concurrency = 1
 274
 275 Reconnect = false                     Data verification = false
 276
 277 Expire-time verification = false           ASCII protocol = true
 278
 279 Binary protocol = false                 Dumping statistic information
 280
 281 periodically = false
 282
 283 Overwrite proportion = 0%             UDP = false
 284
 285 TCP = true                           Limit throughput = false
 286
 287 Facebook test = false                  Replication test = false
 288
 289 Key size, value size and command distribution.
 290 ______________________________________________
 291
 292
 293 All the distributions are read from the configuration file specified by user
 294 with “—cfg_cmd” option. If the user does not specify a configuration file,
 295 memaslap will run with the default distribution (key size = 64,
 296 value size = 1024, get/set = 9:1). For information on how to edit the
 297 configuration file, refer to the “Configuration File” section.
 298
 299 The minimum key size is 16 bytes; the maximum key size is 250 bytes. The
 300 precision of proportion is 0.001. The proportion of distribution will be
 301 rounded to 3 decimal places.
 302
 303 The minimum value size is 1 bytes; the maximum value size is 1M bytes. The
 304 precision of proportion is 0.001. The proportion of distribution will be
 305 rounded to 3 decimal places.
 306 Currently, memaslap only testss set and get commands. And it
 307 testss 100% set and 100% get. For 100% get, it will preset some objects to
 308 the server.
 309
 310
 311 Multi-thread and concurrency
 312 ____________________________
 313
 314
 315 The high performance of memaslap benefits from the special
 316 schedule of thread and concurrency. It’s important to specify the proper
 317 number of them. The default number of threads is 1; the default number of
 318 concurrency is 16. The user can use “—threads” and “--concurrency” to
 319 specify these variables.
 320
 321 If the system tests setting CPU affinity and the number of threads
 322 specified by the user is greater than 1, memaslap will try to
 323 bind each thread to a different CPU core. So if you want to get the best
 324 performance memaslap, it is better to specify the number of
 325 thread equal to the number of CPU cores. The number of threads specified by
 326 the user can also be less or greater than the number of CPU cores. Because
 327 of the limitation of implementation, the number of concurrencies could be
 328 the multiple of the number of threads.
 329
 330 1. For 8 CPU cores system
 331
 332 For example:
 333
 334 --threads=2 --concurrency=128
 335
 336 --threads=8 --concurrency=128
 337
 338 --threads=8 --concurrency=256
 339
 340 --threads=12 --concurrency=144
 341
 342 2. For 16 CPU cores system
 343
 344 For example:
 345
 346 --threads=8 --concurrency=128
 347
 348 --threads=16 --concurrency=256
 349
 350 --threads=16 --concurrency=512
 351
 352 --threads=24 --concurrency=288
 353
 354 The memaslap performs very well, when
 355 used to test the performance of memcached servers.
 356 Most of the time, the bottleneck is the network or
 357 the server. If for some reason the user wants to
 358 limit the performance of memaslap, there
 359 are two ways to do this:
 360
 361 Decrease the number of threads and concurrencies.
 362 Use the option “--tps” that memaslap
 363 provides to limit the throughput. This option allows
 364 the user to get the expected throughput. For
 365 example, assume that the maximum throughput is 50
 366 kops/s for a specific configuration, you can specify
 367 the throughput equal to or less than the maximum
 368 throughput using “--tps” option.
 369
 370
 371 Window size
 372 ___________
 373
 374
 375 Most of the time, the user does not need to specify the window size. The
 376 default window size is 10k. For Schooner Memcached, the user can specify
 377 different window sizes to get different cache miss rates based on the test
 378 case. Memslap testss cache miss rate between 0% and 100%.
 379 If you use this utility to test the performance of Schooner Memcached, you
 380 can specify a proper window size to get the expected cache miss rate. The
 381 formula for calculating window size is as follows:
 382
 383 Assume that the key size is 128 bytes, and the value size is 2048 bytes, and
 384 concurrency=128.
 385
 386 1. Small cache cache_size=1M, 100% cache miss (all data get from SSD).
 387 win_size=10k
 388
 389 2. cache_size=4G
 390
 391 (1). cache miss rate 0%
 392
 393 win_size=8k
 394
 395 (2). cache miss rate 5%
 396
 397 win_size=11k
 398
 399 3. cache_size=16G
 400
 401 (1). cache miss rate 0%
 402
 403 win_size=32k
 404
 405 (2). cache miss
 406
 407 rate 5%
 408
 409 win_size=46k
 410
 411 The formula for calculating window size for cache miss rate 0%:
 412
 413 cache_size / concurrency / (key_size + value_size) \* 0.5
 414
 415 The formula for calculating window size for cache miss rate 5%:
 416
 417 cache_size / concurrency / (key_size + value_size) \* 0.7
 418
 419
 420 Verification
 421 ____________
 422
 423
 424 Memslap testss both data verification and expire-time
 425 verification. The user can use "--verify=" or "-v" to specify the proportion
 426 of data verification. In theory, it testss 100% data verification. The
 427 user can use "--exp_verify=" or "-e" to specify the proportion of
 428 expire-time verification. In theory, it testss 100% expire-time
 429 verification. Specify the "--verbose" options to get more detailed error
 430 information.
 431
 432 For example: --exp_verify=0.01 –verify=0.1 , it means that 1% of the objects
 433 set with expire-time, 10% of the objects gotten will be verified. If the
 434 objects are gotten, memaslap will verify the expire-time and
 435 value.
 436
 437
 438 multi-servers and multi-config
 439 _______________________________
 440
 441
 442 Memslap testss multi-servers based on self-governed thread.
 443 There is a limitation that the number of servers cannot be greater than the
 444 number of threads. Memslap assigns one thread to handle one
 445 server at least. The user can use the "--servers=" or "-s" option to specify
 446 multi-servers.
 447
 448 For example:
 449
 450 --servers=10.1.1.1:11211,10.1.1.2:11212,10.1.1.3:11213 --threads=6 --concurrency=36
 451
 452 The above command means that there are 6 threads, with each thread having 6
 453 concurrencies and that threads 0 and 3 handle server 0 (10.1.1.1); threads 1
 454 and 4 handle server 1 (10.1.1.2); and thread 2 and 5 handle server 2
 455 (10.1.1.3).
 456
 457 All the threads and concurrencies in memaslap are self-governed.
 458
 459 So is memaslap. The user can start up several
 460 memaslap instances. The user can run memaslap on different client
 461 machines to communicate with the same memcached server at the same. It is
 462 recommended that the user start different memaslap on different
 463 machines using the same configuration.
 464
 465
 466 Run with execute number mode or time mode
 467 _________________________________________
 468
 469
 470 The default memaslap runs with time mode. The default run time
 471 is 10 minutes. If it times out, memaslap will exit. Do not
 472 specify both execute number mode and time mode at the same time; just
 473 specify one instead.
 474
 475 For example:
 476
 477 --time=30s (It means the test will run 30 seconds.)
 478
 479 --execute_number=100000 (It means that after running 100000 commands, the test will exit.)
 480
 481
 482 Dump statistic information periodically.
 483 ________________________________________
 484
 485
 486 The user can use "--stat_freq=" or "-S" to specify the frequency.
 487
 488 For example:
 489
 490 --stat_freq=20s
 491
 492 Memslap will dump the statistics of the commands (get and set) at the frequency of every 20
 493 seconds.
 494
 495 For more information on the format of dumping statistic information, refer to “Format of Output” section.
 496
 497
 498 Multi-get
 499 _________
 500
 501
 502 The user can use "--division=" or "-d" to specify multi-get keys count.
 503 Memslap by default does single get with TCP. Memslap also testss data
 504 verification and expire-time verification for multi-get.
 505
 506 Memslap testss multi-get with both TCP and UDP. Because of
 507 the different implementation of the ASCII protocol and binary protocol,
 508 there are some differences between the two. For the ASCII protocol,
 509 memaslap sends one “multi-get” to the server once. For the
 510 binary protocol, memaslap sends several single get commands
 511 together as “multi-get” to the server.
 512
 513
 514 UDP and TCP
 515 ___________
 516
 517
 518 Memslap testss both UDP and TCP. For TCP,
 519 memaslap does not reconnect the memcached server if socket connections are
 520 lost. If all the socket connections are lost or memcached server crashes,
 521 memaslap will exit. If the user specifies the “--reconnect”
 522 option when socket connections are lost, it will reconnect them.
 523
 524 User can use “--udp” to enable the UDP feature, but UDP comes with some
 525 limitations:
 526
 527 UDP cannot set data more than 1400 bytes.
 528
 529 UDP is not testsed by the binary protocol because the binary protocol of
 530 memcached does not tests that.
 531
 532 UDP doesn’t tests reconnection.
 533
 534
 535 Facebook test
 536 _____________
 537
 538
 539 Set data with TCP and multi-get with UDP. Specify the following options:
 540
 541 "--facebook --division=50"
 542
 543 If you want to create thousands of TCP connections, specify the
 544
 545 "--conn_sock=" option.
 546
 547 For example: --facebook --division=50 --conn_sock=200
 548
 549 The above command means that memaslap will do facebook test,
 550 each concurrency has 200 socket TCP connections and one UDP socket.
 551
 552 Memslap sets objects with the TCP socket, and multi-gets 50
 553 objects once with the UDP socket.
 554
 555 If you specify "--division=50", the key size must be less that 25 bytes
 556 because the UDP packet size is 1400 bytes.
 557
 558
 559 Replication test
 560 ________________
 561
 562
 563 For replication test, the user must specify at least two memcached servers.
 564 The user can use “—rep_write=” option to enable feature.
 565
 566 For example:
 567
 568 --servers=10.1.1.1:11211,10.1.1.2:11212 –rep_write=2
 569
 570 The above command means that there are 2 replication memcached servers,
 571 memaslap will set objects to both server 0 and server 1, get
 572 objects which are set to server 0 before from server 1, and also get objects
 573 which are set to server 1 before from server 0. If server 0 crashes,
 574 memaslap will only get objects from server 1. If server 0 comes
 575 back to life again, memaslap will reconnect server 0. If both
 576 server 0 and server 1 crash, memaslap will exit.
 577
 578
 579 Supports thousands of TCP connections
 580 _____________________________________
 581
 582
 583 Start memaslap with "--conn_sock=" or "-n" to enable this
 584 feature. Make sure that your system can tests opening thousands of files
 585 and creating thousands of sockets. However, this feature does not tests
 586 reconnection if sockets disconnect.
 587
 588 For example:
 589
 590 --threads=8 --concurrency=128 --conn_sock=128
 591
 592 The above command means that memaslap starts up 8 threads, each
 593 thread has 16 concurrencies, each concurrency has 128 TCP socket
 594 connections, and the total number of TCP socket connections is 128 \* 128 =
 595 16384.
 596
 597
 598 Supports binary protocol
 599 ________________________
 600
 601
 602 Start memaslap with "--binary" or "-B" options to enable this
 603 feature. It testss all the above features except UDP, because the latest
 604 memcached 1.3.3 does not implement binary UDP protocol.
 605
 606 For example:
 607
 608 --binary
 609
 610 Since memcached 1.3.3 doesn't implement binary UDP protocol,
 611 memaslap does not tests UDP. In addition, memcached 1.3.3 does not tests
 612 multi-get. If you specify "--division=50" option, it just sends 50 get
 613 commands together as “mulit-get” to the server.
 614
 615
 616
 617 ------------------
 618 Configuration file
 619 ------------------
 620
 621
 622 This section describes the format of the configuration file.  By default
 623 when no configuration file is specified memaslap reads the default
 624 one located at ~/.memaslap.cnf.
 625
 626 Below is a sample configuration file:
 627
 628
 629 .. code-block:: perl
 630
 631   ---------------------------------------------------------------------------
 632   #comments should start with '#'
 633   #key
 634   #start_len end_len proportion
 635   #
 636   #key length range from start_len to end_len
 637   #start_len must be equal to or greater than 16
 638   #end_len must be equal to or less than 250
 639   #start_len must be equal to or greater than end_len
 640   #memaslap will generate keys according to the key range
 641   #proportion: indicates keys generated from one range accounts for the total
 642   generated keys
 643   #
 644   #example1: key range 16~100 accounts for 80%
 645   #          key range 101~200 accounts for 10%
 646   #          key range 201~250 accounts for 10%
 647   #          total should be 1 (0.8+0.1+0.1 = 1)
 648   #
 649   #          16 100 0.8
 650   #          101 200 0.1
 651   #          201 249 0.1
 652   #
 653   #example2: all keys length are 128 bytes
 654   #
 655   #          128 128 1
 656   key
 657   128 128 1
 658   #value
 659   #start_len end_len proportion
 660   #
 661   #value length range from start_len to end_len
 662   #start_len must be equal to or greater than 1
 663   #end_len must be equal to or less than 1M
 664   #start_len must be equal to or greater than end_len
 665   #memaslap will generate values according to the value range
 666   #proportion: indicates values generated from one range accounts for the
 667   total generated values
 668   #
 669   #example1: value range 1~1000 accounts for 80%
 670   #          value range 1001~10000 accounts for 10%
 671   #          value range 10001~100000 accounts for 10%
 672   #          total should be 1 (0.8+0.1+0.1 = 1)
 673   #
 674   #          1 1000 0.8
 675   #          1001 10000 0.1
 676   #          10001 100000 0.1
 677   #
 678   #example2: all value length are 128 bytes
 679   #
 680   #          128 128 1
 681   value
 682   2048 2048 1
 683   #cmd
 684   #cmd_type cmd_proportion
 685   #
 686   #currently memaslap only testss get and set command.
 687   #
 688   #cmd_type
 689   #set     0
 690   #get     1
 691   #
 692   #example: set command accounts for 50%
 693   #         get command accounts for 50%
 694   #         total should be 1 (0.5+0.5 = 1)
 695   #
 696   #         cmd
 697   #         0    0.5
 698   #         1    0.5
 699   cmd
 700   0    0.1
 701   1.0 0.9
 702
 703
 704
 705 ----------------
 706 Format of output
 707 ----------------
 708
 709
 710 At the beginning, memaslap displays some configuration information as follows:
 711
 712
 713 servers : 127.0.0.1:11211
 714
 715
 716
 717 threads count: 1
 718
 719
 720
 721 concurrency: 16
 722
 723
 724
 725 run time: 20s
 726
 727
 728
 729 windows size: 10k
 730
 731
 732
 733 set proportion: set_prop=0.10
 734
 735
 736
 737 get proportion: get_prop=0.90
 738
 739
 740
 741 Where
 742 _____
 743
 744
 745
 746 servers : "servers"
 747
 748  The servers used by memaslap.
 749
 750
 751
 752 threads count
 753
 754  The number of threads memaslap runs with.
 755
 756
 757
 758 concurrency
 759
 760  The number of concurrencies memaslap runs with.
 761
 762
 763
 764 run time
 765
 766  How long to run memaslap.
 767
 768
 769
 770 windows size
 771
 772  The task window size of each concurrency.
 773
 774
 775
 776 set proportion
 777
 778  The proportion of set command.
 779
 780
 781
 782 get proportion
 783
 784  The proportion of get command.
 785
 786
 787
 788 The output of dynamic statistics is something like this:
 789
 790
 791 .. code-block:: perl
 792
 793   ---------------------------------------------------------------------------------------------------------------------------------
 794   Get Statistics
 795   Type  Time(s)  Ops   TPS(ops/s)  Net(M/s)  Get_miss  Min(us)  Max(us)
 796   Avg(us)  Std_dev    Geo_dist
 797   Period   5   345826  69165     65.3      0         27      2198     203
 798   95.43      177.29
 799   Global  20  1257935  62896     71.8      0         26      3791     224
 800   117.79     192.60
 801
 802
 803   Set Statistics
 804   Type  Time(s)  Ops   TPS(ops/s)  Net(M/s)  Get_miss  Min(us)  Max(us)
 805   Avg(us)  Std_dev    Geo_dist
 806   Period   5    38425   7685      7.3       0         42      628     240
 807   88.05      220.21
 808   Global   20   139780  6989      8.0       0         37      3790    253
 809   117.93     224.83
 810
 811
 812   Total Statistics
 813   Type  Time(s)  Ops   TPS(ops/s)  Net(M/s)  Get_miss  Min(us)  Max(us)
 814   Avg(us)  Std_dev    Geo_dist
 815   Period   5   384252   76850     72.5      0        27      2198     207
 816   94.72      181.18
 817   Global  20  1397720   69886     79.7      0        26      3791     227
 818   117.93     195.60
 819   ---------------------------------------------------------------------------------------------------------------------------------
 820
 821
 822
 823 Where
 824 _____
 825
 826
 827
 828 Get Statistics
 829
 830  Statistics information of get command
 831
 832
 833
 834 Set Statistics
 835
 836  Statistics information of set command
 837
 838
 839
 840 Total Statistics
 841
 842  Statistics information of both get and set command
 843
 844
 845
 846 Period
 847
 848  Result within a period
 849
 850
 851
 852 Global
 853
 854  Accumulated results
 855
 856
 857
 858 Ops
 859
 860  Total operations
 861
 862
 863
 864 TPS
 865
 866  Throughput, operations/second
 867
 868
 869
 870 Net
 871
 872  The rate of network
 873
 874
 875
 876 Get_miss
 877
 878  How many objects can’t be gotten
 879
 880
 881
 882 Min
 883
 884  The minimum response time
 885
 886
 887
 888 Max
 889
 890  The maximum response time
 891
 892
 893
 894 Avg:
 895
 896  The average response time
 897
 898
 899
 900 Std_dev
 901
 902  Standard deviation of response time
 903
 904
 905
 906 Geo_dist
 907
 908  Geometric distribution based on natural exponential function
 909
 910
 911
 912 At the end, memaslap will output something like this:
 913
 914
 915 .. code-block:: perl
 916
 917    ---------------------------------------------------------------------------------------------------------------------------------
 918    Get Statistics (1257956 events)
 919      Min:        26
 920      Max:      3791
 921      Avg:       224
 922      Geo:    192.60
 923      Std:    116.23
 924                      Log2 Dist:
 925                        4:        0       10    84490   215345
 926                        8:   484890   459823    12543      824
 927                       12:       31
 928
 929     Set Statistics (139782 events)
 930        Min:        37
 931        Max:      3790
 932        Avg:       253
 933        Geo:    224.84
 934        Std:    116.83
 935        Log2 Dist:
 936          4:        0        0     4200 16988
 937          8:    50784    65574 2064      167
 938          12:        5
 939
 940      Total Statistics (1397738 events)
 941          Min:        26
 942          Max:      3791
 943          Avg:       227
 944          Geo:    195.60
 945          Std:    116.60
 946          Log2 Dist:
 947            4:        0       10    88690   232333
 948            8:   535674   525397    14607      991
 949            12:       36
 950
 951    cmd_get: 1257969
 952    cmd_set: 139785
 953    get_misses: 0
 954    verify_misses: 0
 955    verify_failed: 0
 956    expired_get: 0
 957    unexpired_unget: 0
 958    written_bytes: 242516030
 959    read_bytes: 1003702556
 960    object_bytes: 152086080
 961    packet_disorder: 0
 962    packet_drop: 0
 963    udp_timeout: 0
 964
 965    Run time: 20.0s Ops: 1397754 TPS: 69817 Net_rate: 59.4M/s
 966    ---------------------------------------------------------------------------------------------------------------------------------
 967
 968
 969
 970 Where
 971 _____
 972
 973
 974
 975 Get Statistics
 976
 977  Get statistics of response time
 978
 979
 980
 981 Set Statistics
 982
 983  Set statistics of response time
 984
 985
 986
 987 Total Statistics
 988
 989  Both get and set statistics of response time
 990
 991
 992
 993 Min
 994
 995  The accumulated and minimum response time
 996
 997
 998
 999 Max
1000
1001  The accumulated and maximum response time
1002
1003
1004
1005 Avg
1006
1007  The accumulated and average response time
1008
1009
1010
1011 Std
1012
1013  Standard deviation of response time
1014
1015
1016
1017 Log2 Dist
1018
1019  Geometric distribution based on logarithm 2
1020
1021
1022
1023 cmd_get
1024
1025  Total get commands done
1026
1027
1028
1029 cmd_set
1030
1031  Total set commands done
1032
1033
1034
1035 get_misses
1036
1037  How many objects can’t be gotten from server
1038
1039
1040
1041 verify_misses
1042
1043  How many objects need to verify but can’t get them
1044
1045
1046
1047 verify_failed
1048
1049  How many objects with insistent value
1050
1051
1052
1053 expired_get
1054
1055  How many objects are expired but we get them
1056
1057
1058
1059 unexpired_unget
1060
1061  How many objects are unexpired but we can’t get them
1062
1063
1064
1065 written_bytes
1066
1067  Total written bytes
1068
1069
1070
1071 read_bytes
1072
1073  Total read bytes
1074
1075
1076
1077 object_bytes
1078
1079  Total object bytes
1080
1081
1082
1083 packet_disorder
1084
1085  How many UDP packages are disorder
1086
1087
1088
1089 packet_drop
1090
1091  How many UDP packages are lost
1092
1093
1094
1095 udp_timeout
1096
1097  How many times UDP time out happen
1098
1099
1100
1101 Run time
1102
1103  Total run time
1104
1105
1106
1107 Ops
1108
1109  Total operations
1110
1111
1112
1113 TPS
1114
1115  Throughput, operations/second
1116
1117
1118
1119 Net_rate
1120
1121  The average rate of network
1122
1123
1124
1125
1126
1127 -------
1128 OPTIONS
1129 -------
1130
1131
1132 -s, --servers=
1133     List one or more servers to connect. Servers count must be less than
1134     threads count. e.g.: --servers=localhost:1234,localhost:11211
1135
1136 -T, --threads=
1137     Number of threads to startup, better equal to CPU numbers. Default 8.
1138
1139 -c, --concurrency=
1140     Number of concurrency to simulate with load. Default 128.
1141
1142 -n, --conn_sock=
1143     Number of TCP socks per concurrency. Default 1.
1144
1145 -x, --execute_number=
1146     Number of operations(get and set) to execute for the
1147     given test. Default 1000000.
1148
1149 -t, --time=
1150     How long the test to run, suffix: s-seconds, m-minutes, h-hours,
1151     d-days e.g.: --time=2h.
1152
1153 -F, --cfg_cmd=
1154     Load the configure file to get command,key and value distribution list.
1155
1156 -w, --win_size=
1157     Task window size of each concurrency, suffix: K, M e.g.: --win_size=10k.
1158     Default 10k.
1159
1160 -X, --fixed_size=
1161     Fixed length of value.
1162
1163 -v, --verify=
1164     The proportion of date verification, e.g.: --verify=0.01
1165
1166 -d, --division=
1167     Number of keys to multi-get once. Default 1, means single get.
1168
1169 -S, --stat_freq=
1170     Frequency of dumping statistic information. suffix: s-seconds,
1171     m-minutes, e.g.: --resp_freq=10s.
1172
1173 -e, --exp_verify=
1174     The proportion of objects with expire time, e.g.: --exp_verify=0.01.
1175     Default no object with expire time
1176
1177 -o, --overwrite=
1178     The proportion of objects need overwrite, e.g.: --overwrite=0.01.
1179     Default never overwrite object.
1180
1181 -R, --reconnect
1182     Reconnect tests, when connection is closed it will be reconnected.
1183
1184 -U, --udp
1185     UDP tests, default memaslap uses TCP, TCP port and UDP port of
1186     server must be same.
1187
1188 -a, --facebook
1189     Whether it enables facebook test feature, set with TCP and multi-get with UDP.
1190
1191 -B, --binary
1192     Whether it enables binary protocol. Default with ASCII protocol.
1193
1194 -P, --tps=
1195     Expected throughput, suffix: K, e.g.: --tps=10k.
1196
1197 -p, --rep_write=
1198     The first nth servers can write data, e.g.: --rep_write=2.
1199
1200 -b, --verbose
1201     Whether it outputs detailed information when verification fails.
1202
1203 -h, --help
1204     Display this message and then exit.
1205
1206 -V, --version
1207     Display the version of the application and then exit.
1208
1209
1210 --------
1211 EXAMPLES
1212 --------
1213
1214
1215 memaslap -s 127.0.0.1:11211 -S 5s
1216
1217 memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b
1218
1219 memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2
1220
1221 memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k
1222
1223 memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40
1224
1225 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m
1226
1227 memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2
1228
1229
1230 ----
1231 HOME
1232 ----
1233
1234
1235 To find out more information please check:
1236 `http://libmemcached.org/ <http://libmemcached.org/>`_
1237
1238
1239 -------
1240 AUTHORS
1241 -------
1242
1243
1244 Mingqiang Zhuang <mingqiangzhuang@hengtiansoft.com> (Schooner Technolgy)
1245 Brian Aker, <brian@tangent.org>
1246
1247
1248 --------
1249 SEE ALSO
1250 --------
1251
1252 :manpage:`memcached(1)` :manpage:`libmemcached(3)`