I am running Veins simulation with 25 cars and 100 Rsu's. Simulation is running awfully slow. I tried with the example given and the case is same. What can I do ?
I have tried with Release mode, switching off animations, with command mode, increased number of parallel processes from 1 to 4. Nothing is helping, in express mode it slows down to milliseconds.
Update: Simulation has become more slow when more message are sent and received.
With 5 cars and 50 RSU with Range of 500 meter this is my simulation speed:
** Event #27359744 t=46.268980990815 Elapsed: 5387.036s (1h 29m) 46% completed
Speed: ev/sec=4094.07 simsec/sec=0.00195494 ev/simsec=2.09421e+006
Messages: created: 21616816 present: 20679 in FES: 20123
Currently using command mode.
I figured it out why simulation was slow, events per seconds were ev/simsec=2.09421e+006. So I debugged the code and found that for every message RSU receives it sends a message back. So after removing this the simulation is running much faster.
Related
I created a test in JMETER
Add > Sampler > HTTP Request = Get
Server Name = dainikbhaskar.com
No. of threads(users) = 1
Ramp-up period (seconds) = 1,
Loop Count = 1
(My internet connection is a broadband one with the speed 50 MBPS)
I ran the test, ran successful, latency comes as 127 & sometimes less than 100 in subsequent executions.
I switched off my Wi-Fi, connected my laptop with mobile hotspot & executed the same test.
Now the latency is 607, 932, 373, 542, 915
I believe it's happening due to INTERNET CONNECTION SPEED as rest of the inputs are same.
Please confirm whether my perception is correct ? :)
It is correct.
You can also get network latency from https://www.speedtest.net/ or https://fast.com/
Latency is the time from sending the request until first byte of response arrives, so called "Time to first byte"
In JMeter's world:
Latency is Connect Time + Time to send the request + time to get the first byte of response
Elapsed time is Latency + time to get the last byte of the response.
More information:
JMeter Glossary
Understanding Your Reports: Part 1 - What are KPIs?
If you get 5x times higher latency for other connection it means that the majority of time is spend for the packets to travel back and forth. You can see the more precise picture by looking at Network tab of your browser developer tools or using a special solution like Lighthouse
I have weird performance issues with fetch.max.message.bytes parameter in librdkafka consumer implementation (version 0.11). I run some tests using kafkacat over slow speed network link (4 Mbps) and received following results:
1024 bytes = 1.740s
65536 bytes = 2.670s
131072 bytes = 7.070s
When I started debugging protocol messages I noticed a way to high RTT values.
|SEND|rdkafka| Sent FetchRequest (v4, 68 bytes # 0, CorrId 8)
|RECV|rdkafka| Received FetchResponse (v4, 131120 bytes, CorrId 8, rtt 607.68ms)
It seems that increase of fetch.max.message.bytes value causes very high network saturation, but it carries only single message per request.
On the other hand when I try kafka-console-consumer everything runs as expected (I get throughput 500 messages per second over the same network link).
Any ideas or suggestions where to look at?
You are most likely hitting issue #1384 which is a bug with the new v0.11.0 consumer. The bug is particularly evident on slow links or with MessageSets/batches with few messages.
A fix is on the way.
I have the next test plan in JMeter:
on the screenshot you can see the settings for the 1st ThreadGroup, wich has 50% of common amout of request in test plan (in each Thread Group are 10 different subrequests placed).
So, +1 request per second is added in average using these settings.
Then I ran this test and saw this picture (Error % column):
I save errors in file and all these errors have the same text:
<sample t="30129" lt="0" ts="1356710138314" s="false" lb="WebService(SOAP) Request 1" rc="000" rm="**Connection reset**" tn="jp#gc - Stepping Thread Group1 3-247" dt="text" by="0"/>
Server's cpu screenshot:
and for database:
After the errors have appeared my comp started work slowly and slowly (although the errors stopped to appear further)...
And in the same time the server's cpu progressively dropped to 0.
Could you tell me, please,
What is the reason of this error?
Have I reached the server timeout? (Because Max is more than 30s in the table).
UPD. I have rerun test with next settings: 1000 users per 02:46:40 (+1 Thread Group per 10 second and 10 requests inside each new Thread in the Loop).
I.e. I have reduced the time of test and total Thread Groups by 2 times, but save intensivity of Thead's adding.
The results are the same (including cpu usage on the server).
I've received the error «Connection reset» after 990 thread started. There are screenshots:
Any idea?
First, WebService(SOAP) Request is not the best way to test Webservices in JMeter, it will be deprecated in upcoming 2.9 version.
HTTP Sampler is the one to choose as it performs much better.
Second, Connection Reset means your server has cut connection. It could be coming from the CPU which seems high but it's not sure.
If what you call "my comp" is the computer hosting JMeter started working slowly then your JMeter instance is overwhelmed by the number of threads (2003 or more?) you've configured. It can come from a lot of factors, read this:
http://www.dzone.com/links/see_how_to_make_jmeter_run_thousands_of_threads_w.html
I have been testing MongoDB 2.6.7 for the last couple of months using YCSB 0.1.4. I have captured good data comparing SSD to HDD and am producing engineering reports.
After my testing was completed, I wanted to explore the allanbank async driver. When I got it up and running (I am not a developer, so it was a challenge for me), I first wanted to try the rebuilt sync driver. I found performance improvements of 30-100%, depending on the workload, and was very happy with it.
Next, I tried the async driver. I was not able to see much difference between it and my results with the native driver.
The command I'm running is:
./bin/ycsb run mongodb -s -P workloads/workloadb -p mongodb.url=mongodb://192.168.0.13:27017/ycsb -p mongodb.writeConcern=strict -threads 96
Over the course of my testing (mostly with the native driver), I have experimented with more and less threads than 96; turned on "noatime"; tried both xfs and ext4; disabled hyperthreading; disabled half my 12 cores; put the journal on a different drive; changed sync from 60 seconds to 1 second; and checked the network bandwidth between the client and server to ensure its not oversubscribed (10GbE).
Any feedback or suggestions welcome.
The Async move exceeded my expectations. My experience is with the Python Sync (pymongo) and Async driver (motor) and the Async driver achieved greater than 10x the throughput. further, motor is still using pymongo under the hoods but adds the async ability. that could easily be the case with your allanbank driver.
Often the dramatic changes come from threading policies and OS configurations.
Async needn't and shouldn't use any more threads than cores on the VM or machine. For example, if you're server code is spawning a new thread per incoming conn -- then all bets are off. start by looking at the way the driver is being utilized. A 4 core machine uses <= 4 incoming threads.
On the OS level, you may have to fine-tune parameters like net.core.somaxconn, net.core.netdev_max_backlog, sys.fs.file_max, /etc/security/limits.conf nofile and the best place to start is looking at nginx related performance guides including this one. nginx is the server that spearheaded or at least caught the attention of many linux sysadmin enthusiasts. Contrary to popular lore one should reduce your keepalive timeout opposed to lengthen it. The default keep-alive timeout is some absurd (4 hours) number of seconds. you might want to cut the cord in 1 minute. basically, think a short sweet relationship with your clients connections.
Bear in mind that Mongo is not Async so you can use a Mongo driver pool. nevertheless, don't let the driver get stalled on slow queries. cut it off in 5 to 10 seconds using the following equivalents in Java. I'm just cutting and pasting here with no recommendations.
# Specifies a time limit for a query operation. If the specified time is exceeded, the operation will be aborted and ExecutionTimeout is raised. If max_time_ms is None no limit is applied.
# Raises TypeError if max_time_ms is not an integer or None. Raises InvalidOperation if this Cursor has already been used.
CONN_MAX_TIME_MS = None
# socketTimeoutMS: (integer) How long (in milliseconds) a send or receive on a socket can take before timing out. Defaults to None (no timeout).
CLIENT_SOCKET_TIMEOUT_MS=None
# connectTimeoutMS: (integer) How long (in milliseconds) a connection can take to be opened before timing out. Defaults to 20000.
CLIENT_CONNECT_TIMEOUT_MS=20000
# waitQueueTimeoutMS: (integer) How long (in milliseconds) a thread will wait for a socket from the pool if the pool has no free sockets. Defaults to None (no timeout).
CLIENT_WAIT_QUEUE_TIMEOUT_MS=None
# waitQueueMultiple: (integer) Multiplied by max_pool_size to give the number of threads allowed to wait for a socket at one time. Defaults to None (no waiters).
CLIENT_WAIT_QUEUE_MULTIPLY=None
Hopefully you will have the same success. I was ready to bail on Python prior to async
I have the next test plan in JMeter:
on the screenshot you can see the settings for the 1st ThreadGroup, wich has 50% of common amout of request in test plan (in each Thread Group are 10 different subrequests placed).
So, +1 request per second is added in average using these settings.
Then I ran this test and saw this picture (Error % column):
I save errors in file and all these errors have the same text:
<sample t="30129" lt="0" ts="1356710138314" s="false" lb="WebService(SOAP) Request 1" rc="000" rm="**Connection reset**" tn="jp#gc - Stepping Thread Group1 3-247" dt="text" by="0"/>
Server's cpu screenshot:
and for database:
After the errors have appeared my comp started work slowly and slowly (although the errors stopped to appear further)...
And in the same time the server's cpu progressively dropped to 0.
Could you tell me, please,
What is the reason of this error?
Have I reached the server timeout? (Because Max is more than 30s in the table).
UPD. I have rerun test with next settings: 1000 users per 02:46:40 (+1 Thread Group per 10 second and 10 requests inside each new Thread in the Loop).
I.e. I have reduced the time of test and total Thread Groups by 2 times, but save intensivity of Thead's adding.
The results are the same (including cpu usage on the server).
I've received the error «Connection reset» after 990 thread started. There are screenshots:
Any idea?
First, WebService(SOAP) Request is not the best way to test Webservices in JMeter, it will be deprecated in upcoming 2.9 version.
HTTP Sampler is the one to choose as it performs much better.
Second, Connection Reset means your server has cut connection. It could be coming from the CPU which seems high but it's not sure.
If what you call "my comp" is the computer hosting JMeter started working slowly then your JMeter instance is overwhelmed by the number of threads (2003 or more?) you've configured. It can come from a lot of factors, read this:
http://www.dzone.com/links/see_how_to_make_jmeter_run_thousands_of_threads_w.html