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diff --git a/docs/source/bin/memaslap.rst b/docs/source/bin/memaslap.rst new file mode 100644 index 00000000..61060675 --- /dev/null +++ b/docs/source/bin/memaslap.rst @@ -0,0 +1,1252 @@ +================================================== +memaslap - Load testing and benchmarking a server +================================================== + + +-------- +SYNOPSIS +-------- + +memaslap [options] + +.. program:: memaslap + +.. option:: --help + +.. envvar:: MEMCACHED_SERVERS + +----------- +DESCRIPTION +----------- + + +:program:`memaslap` is a load generation and benchmark tool for memcached +servers. It generates configurable workload such as threads, concurrencies, +connections, run time, overwrite, miss rate, key size, value size, get/set +proportion, expected throughput, and so on. Furthermore, it also testss data +verification, expire-time verification, UDP, binary protocol, facebook test, +replication test, multi-get and reconnection, etc. + +Memaslap manages network connections like memcached with +libevent. Each thread of memaslap is bound with a CPU core, all +the threads don't communicate with each other, and there are several socket +connections in each thread. Each connection keeps key size distribution, +value size distribution, and command distribution by itself. + +You can specify servers via the :option:`memslap --servers` option or via the +environment variable :envvar:`MEMCACHED_SERVERS`. + + +-------- +FEATURES +-------- + + +Memslap is developed to for the following purposes: + + +Manages network connections with libevent asynchronously. + + + +Set both TCP and UDP up to use non-blocking IO. + + + +Improves parallelism: higher performance in multi-threads environments. + + + +Improves time efficiency: faster processing speed. + + + +Generates key and value more efficiently; key size distribution and value size distribution are configurable. + + + +Supports get, multi-get, and set commands; command distribution is configurable. + + + +Supports controllable miss rate and overwrite rate. + + + +Supports data and expire-time verification. + + + +Supports dumping statistic information periodically. + + + +Supports thousands of TCP connections. + + + +Supports binary protocol. + + + +Supports facebook test (set with TCP and multi-get with UDP) and replication test. + + + + +------- +DETAILS +------- + + +Effective implementation of network. +____________________________________ + + +For memaslap, both TCP and UDP use non-blocking network IO. All +the network events are managed by libevent as memcached. The network module +of memaslap is similar to memcached. Libevent can ensure +memaslap can handle network very efficiently. + + +Effective implementation of multi-threads and concurrency +_________________________________________________________ + + +Memslap has the similar implementation of multi-threads to +memcached. Memslap creates one or more self-governed threads; +each thread is bound with one CPU core if the system testss setting CPU +core affinity. + +In addition, each thread has a libevent to manage the events of the network; +each thread has one or more self-governed concurrencies; and each +concurrency has one or more socket connections. All the concurrencies don’t +communicate with each other even though they are in the same thread. + +Memslap can create thousands of socket connections, and each +concurrency has tens of socket connections. Each concurrency randomly or +sequentially selects one socket connection from its socket connection pool +to run, so memaslap can ensure each concurrency handles one +socket connection at any given time. Users can specify the number of +concurrency and socket connections of each concurrency according to their +expected workload. + + +Effective implementation of generating key and value +____________________________________________________ + + +In order to improve time efficiency and space efficiency, +memaslap creates a random characters table with 10M characters. All the +suffixes of keys and values are generated from this random characters table. + +Memslap uses the offset in the character table and the length +of the string to identify a string. It can save much memory. +Each key contains two parts, a prefix and a suffix. The prefix is an +uint64_t, 8 bytes. In order to verify the data set before, +memaslap need to ensure each key is unique, so it uses the prefix to identify +a key. The prefix cannot include illegal characters, such as ‘\r’, ‘\n’, +‘\0’ and ‘ ‘. And memaslap has an algorithm to ensure that. + +Memslap doesn’t generate all the objects (key-value pairs) at +the beginning. It only generates enough objects to fill the task window +(default 10K objects) of each concurrency. Each object has the following +basic information, key prefix, key suffix offset in the character table, key +length, value offset in the character table, and value length. + +In the work process, each concurrency sequentially or randomly selects an +object from the window to do set operation or get operation. At the same +time, each concurrency kicks objects out of its window and adds new object +into it. + + +Simple but useful task scheduling +_________________________________ + + +Memslap uses libevent to schedule all the concurrencies of +threads, and each concurrency schedules tasks based on the local task +window. Memslap assumes that if each concurrency keeps the same +key distribution, value distribution and commands distribution, from +outside, memaslap keeps all the distribution as a whole. +Each task window includes a lot of objects, each object stores its basic +information, such as key, value, expire time, and so on. At any time, all +the objects in the window keep the same and fixed key and value +distribution. If an object is overwritten, the value of the object will be +updated. Memslap verifies the data or expire-time according to +the object information stored in the task window. + +Libevent selects which concurrency to handle based on a specific network +event. Then the concurrency selects which command (get or set) to operate +based on the command distribution. If it needs to kick out an old object and +add a new object, in order to keep the same key and value distribution, the +new object must have the same key length and value length. + +If memcached server has two cache layers (memory and SSD), running +memaslap with different window sizes can get different cache +miss rates. If memaslap adds enough objects into the windows at +the beginning, and the cache of memcached cannot store all the objects +initialized, then memaslap will get some objects from the second +cache layer. It causes the first cache layer to miss. So the user can +specify the window size to get the expected miss rate of the first cache +layer. + + +Useful implementation of multi-servers , UDP, TCP, multi-get and binary protocol +________________________________________________________________________________ + + +Because each thread is self-governed, memaslap can assign +different threads to handle different memcached servers. This is just one of +the ways in which memaslap tests multiple servers. The only +limitation is that the number of servers cannot be greater than the number +of threads. The other way to test multiple servers is for replication +test. Each concurrency has one socket connection to each memcached server. +For the implementation, memaslap can set some objects to one +memcached server, and get these objects from the other servers. + +By default, Memslap does single get. If the user specifies +multi-get option, memaslap will collect enough get commands and +pack and send the commands together. + +Memslap testss both the ASCII protocol and binary protocol, +but it runs on the ASCII protocol by default. +Memslap by default runs on the TCP protocol, but it also +tests UDP. Because UDP is unreliable, dropped packages and out-of-order +packages may occur. Memslap creates a memory buffer to handle +these problems. Memslap tries to read all the response data of +one command from the server and reorders the response data. If some packages +get lost, the waiting timeout mechanism can ensure half-baked packages will +be discarded and the next command will be sent. + + + +----- +USAGE +----- + + +Below are some usage samples: + + +memaslap -s 127.0.0.1:11211 -S 5s + + + +memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b + + + +memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2 + + + +memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k + + + +memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40 + + + +memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m + + + +memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2 + + + +The user must specify one server at least to run memaslap. The +rest of the parameters have default values, as shown below: + +Thread number = 1 Concurrency = 16 + +Run time = 600 seconds Configuration file = NULL + +Key size = 64 Value size = 1024 + +Get/set = 9:1 Window size = 10k + +Execute number = 0 Single get = true + +Multi-get = false Number of sockets of each concurrency = 1 + +Reconnect = false Data verification = false + +Expire-time verification = false ASCII protocol = true + +Binary protocol = false Dumping statistic information + +periodically = false + +Overwrite proportion = 0% UDP = false + +TCP = true Limit throughput = false + +Facebook test = false Replication test = false + +Key size, value size and command distribution. +______________________________________________ + + +All the distributions are read from the configuration file specified by user +with “—cfg_cmd” option. If the user does not specify a configuration file, +memaslap will run with the default distribution (key size = 64, +value size = 1024, get/set = 9:1). For information on how to edit the +configuration file, refer to the “Configuration File” section. + +The minimum key size is 16 bytes; the maximum key size is 250 bytes. The +precision of proportion is 0.001. The proportion of distribution will be +rounded to 3 decimal places. + +The minimum value size is 1 bytes; the maximum value size is 1M bytes. The +precision of proportion is 0.001. The proportion of distribution will be +rounded to 3 decimal places. +Currently, memaslap only testss set and get commands. And it +testss 100% set and 100% get. For 100% get, it will preset some objects to +the server. + + +Multi-thread and concurrency +____________________________ + + +The high performance of memaslap benefits from the special +schedule of thread and concurrency. It’s important to specify the proper +number of them. The default number of threads is 1; the default number of +concurrency is 16. The user can use “—threads” and “--concurrency” to +specify these variables. + +If the system tests setting CPU affinity and the number of threads +specified by the user is greater than 1, memaslap will try to +bind each thread to a different CPU core. So if you want to get the best +performance memaslap, it is better to specify the number of +thread equal to the number of CPU cores. The number of threads specified by +the user can also be less or greater than the number of CPU cores. Because +of the limitation of implementation, the number of concurrencies could be +the multiple of the number of threads. + +1. For 8 CPU cores system + +For example: + +--threads=2 --concurrency=128 + +--threads=8 --concurrency=128 + +--threads=8 --concurrency=256 + +--threads=12 --concurrency=144 + +2. For 16 CPU cores system + +For example: + +--threads=8 --concurrency=128 + +--threads=16 --concurrency=256 + +--threads=16 --concurrency=512 + +--threads=24 --concurrency=288 + +The memaslap performs very well, when +used to test the performance of memcached servers. +Most of the time, the bottleneck is the network or +the server. If for some reason the user wants to +limit the performance of memaslap, there +are two ways to do this: + +Decrease the number of threads and concurrencies. +Use the option “--tps” that memaslap +provides to limit the throughput. This option allows +the user to get the expected throughput. For +example, assume that the maximum throughput is 50 +kops/s for a specific configuration, you can specify +the throughput equal to or less than the maximum +throughput using “--tps” option. + + +Window size +___________ + + +Most of the time, the user does not need to specify the window size. The +default window size is 10k. For Schooner Memcached, the user can specify +different window sizes to get different cache miss rates based on the test +case. Memslap testss cache miss rate between 0% and 100%. +If you use this utility to test the performance of Schooner Memcached, you +can specify a proper window size to get the expected cache miss rate. The +formula for calculating window size is as follows: + +Assume that the key size is 128 bytes, and the value size is 2048 bytes, and +concurrency=128. + +1. Small cache cache_size=1M, 100% cache miss (all data get from SSD). +win_size=10k + +2. cache_size=4G + +(1). cache miss rate 0% + +win_size=8k + +(2). cache miss rate 5% + +win_size=11k + +3. cache_size=16G + +(1). cache miss rate 0% + +win_size=32k + +(2). cache miss + +rate 5% + +win_size=46k + +The formula for calculating window size for cache miss rate 0%: + +cache_size / concurrency / (key_size + value_size) \* 0.5 + +The formula for calculating window size for cache miss rate 5%: + +cache_size / concurrency / (key_size + value_size) \* 0.7 + + +Verification +____________ + + +Memslap testss both data verification and expire-time +verification. The user can use "--verify=" or "-v" to specify the proportion +of data verification. In theory, it testss 100% data verification. The +user can use "--exp_verify=" or "-e" to specify the proportion of +expire-time verification. In theory, it testss 100% expire-time +verification. Specify the "--verbose" options to get more detailed error +information. + +For example: --exp_verify=0.01 –verify=0.1 , it means that 1% of the objects +set with expire-time, 10% of the objects gotten will be verified. If the +objects are gotten, memaslap will verify the expire-time and +value. + + +multi-servers and multi-config +_______________________________ + + +Memslap testss multi-servers based on self-governed thread. +There is a limitation that the number of servers cannot be greater than the +number of threads. Memslap assigns one thread to handle one +server at least. The user can use the "--servers=" or "-s" option to specify +multi-servers. + +For example: + +--servers=10.1.1.1:11211,10.1.1.2:11212,10.1.1.3:11213 --threads=6 --concurrency=36 + +The above command means that there are 6 threads, with each thread having 6 +concurrencies and that threads 0 and 3 handle server 0 (10.1.1.1); threads 1 +and 4 handle server 1 (10.1.1.2); and thread 2 and 5 handle server 2 +(10.1.1.3). + +All the threads and concurrencies in memaslap are self-governed. + +So is memaslap. The user can start up several +memaslap instances. The user can run memaslap on different client +machines to communicate with the same memcached server at the same. It is +recommended that the user start different memaslap on different +machines using the same configuration. + + +Run with execute number mode or time mode +_________________________________________ + + +The default memaslap runs with time mode. The default run time +is 10 minutes. If it times out, memaslap will exit. Do not +specify both execute number mode and time mode at the same time; just +specify one instead. + +For example: + +--time=30s (It means the test will run 30 seconds.) + +--execute_number=100000 (It means that after running 100000 commands, the test will exit.) + + +Dump statistic information periodically. +________________________________________ + + +The user can use "--stat_freq=" or "-S" to specify the frequency. + +For example: + +--stat_freq=20s + +Memslap will dump the statistics of the commands (get and set) at the frequency of every 20 +seconds. + +For more information on the format of dumping statistic information, refer to “Format of Output” section. + + +Multi-get +_________ + + +The user can use "--division=" or "-d" to specify multi-get keys count. +Memslap by default does single get with TCP. Memslap also testss data +verification and expire-time verification for multi-get. + +Memslap testss multi-get with both TCP and UDP. Because of +the different implementation of the ASCII protocol and binary protocol, +there are some differences between the two. For the ASCII protocol, +memaslap sends one “multi-get” to the server once. For the +binary protocol, memaslap sends several single get commands +together as “multi-get” to the server. + + +UDP and TCP +___________ + + +Memslap testss both UDP and TCP. For TCP, +memaslap does not reconnect the memcached server if socket connections are +lost. If all the socket connections are lost or memcached server crashes, +memaslap will exit. If the user specifies the “--reconnect” +option when socket connections are lost, it will reconnect them. + +User can use “--udp” to enable the UDP feature, but UDP comes with some +limitations: + +UDP cannot set data more than 1400 bytes. + +UDP is not testsed by the binary protocol because the binary protocol of +memcached does not tests that. + +UDP doesn’t tests reconnection. + + +Facebook test +_____________ + + +Set data with TCP and multi-get with UDP. Specify the following options: + +"--facebook --division=50" + +If you want to create thousands of TCP connections, specify the + +"--conn_sock=" option. + +For example: --facebook --division=50 --conn_sock=200 + +The above command means that memaslap will do facebook test, +each concurrency has 200 socket TCP connections and one UDP socket. + +Memslap sets objects with the TCP socket, and multi-gets 50 +objects once with the UDP socket. + +If you specify "--division=50", the key size must be less that 25 bytes +because the UDP packet size is 1400 bytes. + + +Replication test +________________ + + +For replication test, the user must specify at least two memcached servers. +The user can use “—rep_write=” option to enable feature. + +For example: + +--servers=10.1.1.1:11211,10.1.1.2:11212 –rep_write=2 + +The above command means that there are 2 replication memcached servers, +memaslap will set objects to both server 0 and server 1, get +objects which are set to server 0 before from server 1, and also get objects +which are set to server 1 before from server 0. If server 0 crashes, +memaslap will only get objects from server 1. If server 0 comes +back to life again, memaslap will reconnect server 0. If both +server 0 and server 1 crash, memaslap will exit. + + +Supports thousands of TCP connections +_____________________________________ + + +Start memaslap with "--conn_sock=" or "-n" to enable this +feature. Make sure that your system can tests opening thousands of files +and creating thousands of sockets. However, this feature does not tests +reconnection if sockets disconnect. + +For example: + +--threads=8 --concurrency=128 --conn_sock=128 + +The above command means that memaslap starts up 8 threads, each +thread has 16 concurrencies, each concurrency has 128 TCP socket +connections, and the total number of TCP socket connections is 128 \* 128 = +16384. + + +Supports binary protocol +________________________ + + +Start memaslap with "--binary" or "-B" options to enable this +feature. It testss all the above features except UDP, because the latest +memcached 1.3.3 does not implement binary UDP protocol. + +For example: + +--binary + +Since memcached 1.3.3 doesn't implement binary UDP protocol, +memaslap does not tests UDP. In addition, memcached 1.3.3 does not tests +multi-get. If you specify "--division=50" option, it just sends 50 get +commands together as “mulit-get” to the server. + + + +------------------ +Configuration file +------------------ + + +This section describes the format of the configuration file. By default +when no configuration file is specified memaslap reads the default +one located at ~/.memaslap.cnf. + +Below is a sample configuration file: + + +.. code-block:: perl + + --------------------------------------------------------------------------- + #comments should start with '#' + #key + #start_len end_len proportion + # + #key length range from start_len to end_len + #start_len must be equal to or greater than 16 + #end_len must be equal to or less than 250 + #start_len must be equal to or greater than end_len + #memaslap will generate keys according to the key range + #proportion: indicates keys generated from one range accounts for the total + generated keys + # + #example1: key range 16~100 accounts for 80% + # key range 101~200 accounts for 10% + # key range 201~250 accounts for 10% + # total should be 1 (0.8+0.1+0.1 = 1) + # + # 16 100 0.8 + # 101 200 0.1 + # 201 249 0.1 + # + #example2: all keys length are 128 bytes + # + # 128 128 1 + key + 128 128 1 + #value + #start_len end_len proportion + # + #value length range from start_len to end_len + #start_len must be equal to or greater than 1 + #end_len must be equal to or less than 1M + #start_len must be equal to or greater than end_len + #memaslap will generate values according to the value range + #proportion: indicates values generated from one range accounts for the + total generated values + # + #example1: value range 1~1000 accounts for 80% + # value range 1001~10000 accounts for 10% + # value range 10001~100000 accounts for 10% + # total should be 1 (0.8+0.1+0.1 = 1) + # + # 1 1000 0.8 + # 1001 10000 0.1 + # 10001 100000 0.1 + # + #example2: all value length are 128 bytes + # + # 128 128 1 + value + 2048 2048 1 + #cmd + #cmd_type cmd_proportion + # + #currently memaslap only testss get and set command. + # + #cmd_type + #set 0 + #get 1 + # + #example: set command accounts for 50% + # get command accounts for 50% + # total should be 1 (0.5+0.5 = 1) + # + # cmd + # 0 0.5 + # 1 0.5 + cmd + 0 0.1 + 1.0 0.9 + + + +---------------- +Format of output +---------------- + + +At the beginning, memaslap displays some configuration information as follows: + + +servers : 127.0.0.1:11211 + + + +threads count: 1 + + + +concurrency: 16 + + + +run time: 20s + + + +windows size: 10k + + + +set proportion: set_prop=0.10 + + + +get proportion: get_prop=0.90 + + + +Where +_____ + + + +servers : "servers" + + The servers used by memaslap. + + + +threads count + + The number of threads memaslap runs with. + + + +concurrency + + The number of concurrencies memaslap runs with. + + + +run time + + How long to run memaslap. + + + +windows size + + The task window size of each concurrency. + + + +set proportion + + The proportion of set command. + + + +get proportion + + The proportion of get command. + + + +The output of dynamic statistics is something like this: + + +.. code-block:: perl + + --------------------------------------------------------------------------------------------------------------------------------- + Get Statistics + Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us) + Avg(us) Std_dev Geo_dist + Period 5 345826 69165 65.3 0 27 2198 203 + 95.43 177.29 + Global 20 1257935 62896 71.8 0 26 3791 224 + 117.79 192.60 + + + Set Statistics + Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us) + Avg(us) Std_dev Geo_dist + Period 5 38425 7685 7.3 0 42 628 240 + 88.05 220.21 + Global 20 139780 6989 8.0 0 37 3790 253 + 117.93 224.83 + + + Total Statistics + Type Time(s) Ops TPS(ops/s) Net(M/s) Get_miss Min(us) Max(us) + Avg(us) Std_dev Geo_dist + Period 5 384252 76850 72.5 0 27 2198 207 + 94.72 181.18 + Global 20 1397720 69886 79.7 0 26 3791 227 + 117.93 195.60 + --------------------------------------------------------------------------------------------------------------------------------- + + + +Where +_____ + + + +Get Statistics + + Statistics information of get command + + + +Set Statistics + + Statistics information of set command + + + +Total Statistics + + Statistics information of both get and set command + + + +Period + + Result within a period + + + +Global + + Accumulated results + + + +Ops + + Total operations + + + +TPS + + Throughput, operations/second + + + +Net + + The rate of network + + + +Get_miss + + How many objects can’t be gotten + + + +Min + + The minimum response time + + + +Max + + The maximum response time + + + +Avg: + + The average response time + + + +Std_dev + + Standard deviation of response time + + + +Geo_dist + + Geometric distribution based on natural exponential function + + + +At the end, memaslap will output something like this: + + +.. code-block:: perl + + --------------------------------------------------------------------------------------------------------------------------------- + Get Statistics (1257956 events) + Min: 26 + Max: 3791 + Avg: 224 + Geo: 192.60 + Std: 116.23 + Log2 Dist: + 4: 0 10 84490 215345 + 8: 484890 459823 12543 824 + 12: 31 + + Set Statistics (139782 events) + Min: 37 + Max: 3790 + Avg: 253 + Geo: 224.84 + Std: 116.83 + Log2 Dist: + 4: 0 0 4200 16988 + 8: 50784 65574 2064 167 + 12: 5 + + Total Statistics (1397738 events) + Min: 26 + Max: 3791 + Avg: 227 + Geo: 195.60 + Std: 116.60 + Log2 Dist: + 4: 0 10 88690 232333 + 8: 535674 525397 14607 991 + 12: 36 + + cmd_get: 1257969 + cmd_set: 139785 + get_misses: 0 + verify_misses: 0 + verify_failed: 0 + expired_get: 0 + unexpired_unget: 0 + written_bytes: 242516030 + read_bytes: 1003702556 + object_bytes: 152086080 + packet_disorder: 0 + packet_drop: 0 + udp_timeout: 0 + + Run time: 20.0s Ops: 1397754 TPS: 69817 Net_rate: 59.4M/s + --------------------------------------------------------------------------------------------------------------------------------- + + + +Where +_____ + + + +Get Statistics + + Get statistics of response time + + + +Set Statistics + + Set statistics of response time + + + +Total Statistics + + Both get and set statistics of response time + + + +Min + + The accumulated and minimum response time + + + +Max + + The accumulated and maximum response time + + + +Avg + + The accumulated and average response time + + + +Std + + Standard deviation of response time + + + +Log2 Dist + + Geometric distribution based on logarithm 2 + + + +cmd_get + + Total get commands done + + + +cmd_set + + Total set commands done + + + +get_misses + + How many objects can’t be gotten from server + + + +verify_misses + + How many objects need to verify but can’t get them + + + +verify_failed + + How many objects with insistent value + + + +expired_get + + How many objects are expired but we get them + + + +unexpired_unget + + How many objects are unexpired but we can’t get them + + + +written_bytes + + Total written bytes + + + +read_bytes + + Total read bytes + + + +object_bytes + + Total object bytes + + + +packet_disorder + + How many UDP packages are disorder + + + +packet_drop + + How many UDP packages are lost + + + +udp_timeout + + How many times UDP time out happen + + + +Run time + + Total run time + + + +Ops + + Total operations + + + +TPS + + Throughput, operations/second + + + +Net_rate + + The average rate of network + + + + + +------- +OPTIONS +------- + + +-s, --servers= + List one or more servers to connect. Servers count must be less than + threads count. e.g.: --servers=localhost:1234,localhost:11211 + +-T, --threads= + Number of threads to startup, better equal to CPU numbers. Default 8. + +-c, --concurrency= + Number of concurrency to simulate with load. Default 128. + +-n, --conn_sock= + Number of TCP socks per concurrency. Default 1. + +-x, --execute_number= + Number of operations(get and set) to execute for the + given test. Default 1000000. + +-t, --time= + How long the test to run, suffix: s-seconds, m-minutes, h-hours, + d-days e.g.: --time=2h. + +-F, --cfg_cmd= + Load the configure file to get command,key and value distribution list. + +-w, --win_size= + Task window size of each concurrency, suffix: K, M e.g.: --win_size=10k. + Default 10k. + +-X, --fixed_size= + Fixed length of value. + +-v, --verify= + The proportion of date verification, e.g.: --verify=0.01 + +-d, --division= + Number of keys to multi-get once. Default 1, means single get. + +-S, --stat_freq= + Frequency of dumping statistic information. suffix: s-seconds, + m-minutes, e.g.: --resp_freq=10s. + +-e, --exp_verify= + The proportion of objects with expire time, e.g.: --exp_verify=0.01. + Default no object with expire time + +-o, --overwrite= + The proportion of objects need overwrite, e.g.: --overwrite=0.01. + Default never overwrite object. + +-R, --reconnect + Reconnect tests, when connection is closed it will be reconnected. + +-U, --udp + UDP tests, default memaslap uses TCP, TCP port and UDP port of + server must be same. + +-a, --facebook + Whether it enables facebook test feature, set with TCP and multi-get with UDP. + +-B, --binary + Whether it enables binary protocol. Default with ASCII protocol. + +-P, --tps= + Expected throughput, suffix: K, e.g.: --tps=10k. + +-p, --rep_write= + The first nth servers can write data, e.g.: --rep_write=2. + +-b, --verbose + Whether it outputs detailed information when verification fails. + +-h, --help + Display this message and then exit. + +-V, --version + Display the version of the application and then exit. + + +-------- +EXAMPLES +-------- + + +memaslap -s 127.0.0.1:11211 -S 5s + +memaslap -s 127.0.0.1:11211 -t 2m -v 0.2 -e 0.05 -b + +memaslap -s 127.0.0.1:11211 -F config -t 2m -w 40k -S 20s -o 0.2 + +memaslap -s 127.0.0.1:11211 -F config -t 2m -T 4 -c 128 -d 20 -P 40k + +memaslap -s 127.0.0.1:11211 -F config -t 2m -d 50 -a -n 40 + +memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m + +memaslap -s 127.0.0.1:11211,127.0.0.1:11212 -F config -t 2m -p 2 + + +---- +HOME +---- + + +To find out more information please check: +`http://libmemcached.org/ <http://libmemcached.org/>`_ + + +------- +AUTHORS +------- + + +Mingqiang Zhuang <mingqiangzhuang@hengtiansoft.com> (Schooner Technolgy) +Brian Aker, <brian@tangent.org> + + +-------- +SEE ALSO +-------- + +:manpage:`memcached(1)` :manpage:`libmemcached(3)` |