ali_jstorm | 使用阿里中间件RocketMQ、Tair、jstorm对双十一实时交易进行实时计算 | Wifi library
kandi X-RAY | ali_jstorm Summary
kandi X-RAY | ali_jstorm Summary
题目:模拟实时统计阿里双十一交易数据 赛题描述:我们将脱敏后的双11交易数据存储在RocketMQ中,选手利用JStorm从RocketMQ拉取数据,按照要求实时计算出结果,并将结果写入Tair。我们约定用整分时刻对应的时间戳来标识这一分钟,比如2015/11/11 08:11:00分钟对应的整分时间戳为1447200660,那么我们就用这个时间戳来表示这一分钟,即2015/11/11 08:11:00~2015/11/11 08:12::00(不包含这一时刻)。 选手需要计算的统计值如下: 1、分平台(淘宝、天猫)每分钟的交易金额,即计算每一分钟内的交易值。比如计算2015/11/11 11:11:00这一分钟的淘宝交易金额,就是统计从11:11:00分开始到11:12:00(不包含该时刻)这一分钟内的淘宝的交易总金额; 2、每整分时刻无线和PC端总交易金额比值;注意这里统计的是整分时刻对应的总交易比值,要将过去发生的所有交易都计算进去。比如计算2015/11/11 11:11:00整分时刻的交易比值,那么需要统计从交易开始时间到2015/11/11 11:12:00(不包含该时刻)这一区间内所有的交易值,来计算无线和PC端的比值; 最终存储到Tair 中的数据是key-value 的结构,key字符串格式, value是number类型。 key 统一以“固定前缀_teamcode_整分时间戳”方式命名的字符串,整分时间戳就是整分时刻对应的时间戳,例如2015/11/11 08:11:00分钟对应的时间戳为1447200660(注意是10位数),即该时刻的整分时间戳。其中teamcode是每支队伍唯一的标识。 (1)淘宝每分钟的交易金额的key是“platformTaobao_teamcode_整分时间戳”,值都是number类型;例如存入Tair的分平台淘宝实时交易金额格式如下:{"platformTaobao_1234auu_1447200660": 100} (2)天猫每分钟的交易金额的key是“platformTmall_ teamcode 整分时间戳”,值都是number类型;例如存入Tair的分平台天猫实时交易金额格式如下:{"platformTmall_1234auu_1447200660": 200} (3) 每整分时刻无线和PC端总交易金额比值的key为“ratio teamcode_整分时间戳”, 值是一个保留两位小数的number类型。例如存入Tair的无线和PC端实时交易金额比值格式如下:{"ratio_1234auu_1447200660": 2.12} 最终选手提交的代码,会跑在我们后台部署的集群上,我们后台部署的产品版本是:JStorm-2.1.1,RocketMQ-3.2.6,Tair-2.3.5。.
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Top functions reviewed by kandi - BETA
- Server_name
- Write Kryo object to byte array
- Creates a table message
- Create payment message
- Open spout
- Make a new push consumer
- Initialize collector
- Triggered when the trade topic is newer
- This method consumes messages from the queue
- Reads a Kryo object from a byte array
- Prepare for testing
- Write second pair
- Execute the sum of money sums
- Private helper
- Get next tuple from queue
- Main entry point
- Main entry point
- This method is called when a tuple sums are available
- This method executes a tuple
- Add TupleMessage to queue
- Prepare thread
- Initialize storm pool
- Starts the push consumer
- Execute payment method
- Entry point
- Emits a tuple to the collector
ali_jstorm Key Features
ali_jstorm Examples and Code Snippets
Community Discussions
Trending Discussions on Wifi
QUESTION
Even with all the permissions granted the startScan() function still returns false. So my question is: is there a way to scan access points on android 29 or higher?
...ANSWER
Answered 2022-Apr-05 at 08:31The problem was in asking the user for permission. My working code
-Manifest:
-And for asking user for permissions I used EasyPermissions:
QUESTION
I need to develop a feature that is required checking Wi-Fi settings state 'ON' or 'OFF' even if not connected to a WiFi network on Android! I need to display a pop up!
...ANSWER
Answered 2022-Apr-01 at 19:12I think you should to use ConnectivityManager
.
QUESTION
I've got a router Mikrotik hAP AC2. Recently I've updated RouterOS to version 7.1.3 and have found that 5GHz access point has issues.
My notebook sometimes disconnects from 5GHz wlan, and one of smartphones in my family doesn't connect to 5GHz at all.
Here is the plot of wifi signal strength, that I've collected using my notebook located in direct visibility of the router at the distance of about 5-6m.
Cyan line shows 2.4GHz signal and red line shows 5GHz signal. Numbers are -42dbm for 2.4GHz and -68dbm for 5GHz.
My impression is that generally this is not normal. I repeat, there were no obstacles between the notebook and the router, only thin air.
I've tried to reset configuration for 5GHz wlan, change its region, but without success.
How can I fix this?
Here are current settings:
...ANSWER
Answered 2022-Mar-24 at 12:305GHz Wifi is always lower strength than 2.4GHz, it's physics. 5GHz originally improved performance due to moving away from the then congested 2.4GHz band, however, now 5GHz is just as common so despite having a wider range of frequencies it still ends up congested.
5GHz allows for higher throughput while having the disadvantage of being attenuated quicker due to the higher frequency
2.4GHz has a lower data throughput but isn't attenuated as easily.
QUESTION
I'm working on a Wifi auto connect feature and I am shocked how broken that API is.
I'm using now 5 different APIs and I still don't get it in a way the user would expect it.
I have a setting to enable wifi auto connection on Android 10+ I'll try this:
- Check if I hold the
ACCESS_WIFI_STATE
permission with: ...
ANSWER
Answered 2022-Mar-22 at 11:19Well just a half answer, but it might help anyway. Here is how I get the current SSID of the user (you need to hold the location permission):
QUESTION
I need to get the RSSI of the networks and they MAC addresss to a IPS (indoor position system) program. I was able to get ssid, signal strength and security using the sample code, but not mac addresses. I tryed to use this, but itsn't working:
...ANSWER
Answered 2021-Oct-06 at 12:02Maybe the Arduino framework doesn't give this information up easily, but the underlying ESP IDF framework certainly does. The AP-s MAC is called BSSID. Adapting this example scan.c:
QUESTION
I think there's a way to generate a wifi qr with pillow and qrcode library in python. I had searched in the internet and there's no information.
I will apreciate your help. Thank's
-Zateward
...ANSWER
Answered 2022-Feb-18 at 02:16Yes there is. QR codes are just images that are easy for a computer to decode via taking a picture into something useful.
QR codes are just text/strings encoded into an image.
Python has a library called qrcode.
Mobile phone support a specific format of text that tells it to try and connect to a wifi network. This wiki shows an example of what that connection string would look like.
So here is the steps.
- Create a wifi connection string that mobile phones support.
- Pass that string into qrcode to generate a PIL image.
- Do what you want with that PIL image.
QUESTION
When I use Wireshark to capture traffics with my wlan card with monitor mode already set, it only displays 802.11 frames. However, if I use Wireshark with managed mode wlan(promiscuous mode), it certainly displays 802.3 frames.
I searched for some related information and found out that 'network bridging' allows devices to convert 802.11 wireless packets to 802.3 packets. In case of packet capturing, pcap allows conversion.
(link: How to real time convert wireless packet(802.11) to Ethernet packet(802.3) in windows?)
So, Why is 802.11 to 802.3 frame conversion impossible when using monitor mode(not associated to the wireless network)?
Below are pictures of the situation. Thank you in advance.
...ANSWER
Answered 2022-Jan-31 at 00:39For one thing, not all 802.11 packets have Ethernet equivalents; only data packets do. In monitor mode, in addition to data packets, control and management packets can be captured - you're seeing those types of packets in your monitor-mode capture.
For another thing, when capturing in monitor mode on a "protected" network (WEP, WPA), data packets are encrypted (to protect them from being sniffed), and can't be converted to Ethernet packets until they're decrypted. Under some circumstances, Wireshark can decrypt them, but Wireshark doesn't do any conversion from 802.11 to 802.3 in any circumstances - when not capturing in monitor mode, the 802.11 adapter converts data packets to 802.3 packets after decrypting them, and doesn't show non-data packets to the host.
QUESTION
I am working to connect 2 linux machines, each with this USB Dongle: https://www.tp-link.com/us/home-networking/usb-adapter/archer-t2u-nano/, to an ad-hoc WiFi network managed by B.A.T.M.A.N ( batman-adv ).
When run, this scripts show that both devices are joined to the same ad-hoc/IBSS network.
I statically assigned ip addresses and routes to both 'bat0' devices. However, I cannot ping or otherwise use the connection between the two devices.
What am I doing wrong and how can I use the mesh network in Linux between the connected client and server? Thanks.
My 'server' node is configured with this script:
...ANSWER
Answered 2022-Jan-24 at 00:31The answer really is that you need a WiFi radio that actually correclty implements Ad-Hoc/IBSS networking in the driver stack.
QUESTION
I am transferring photo peer to peer. All things works fine but I am not able to get the photo(file) transfer speed i.g internet speed. Like MB the file is transferred. Second I want to fetch the size of that file.
We are passing photo in data format using MCSession
Due to privacy I cannot add the project code here but I will share the refrence github project that I followed. In project I am passing string and In my case its Photo. All things are same.
I checked in Stackoverflow but not found any accurate answer!
Reference Project Link: https://github.com/YogeshPateliOS/MultipeerConnectivity-.git
Thank You!
...ANSWER
Answered 2022-Jan-13 at 13:19TLDR: If you do not want to read the long explanation and get straight to the code, all the ideas below are brought together and can be tested by downloading my public repository which has comments to explain all of this.
So here are my suggestions on how you can achieve this
After reviewing your code, I see that you are using the following function to send data
QUESTION
I've searched for some information about frame structure in wifi and ethernet in the Data Link layer and found out that the two frames look quite different. I am wondering if there is some method in the router that converts wifi frame to ethernet frame in a such network where wireless network is connected to wired network, like WLAN. Since I'm really new to this field, I may have some misunderstanding issues. Thank you.
...ANSWER
Answered 2022-Jan-01 at 13:40Connecting different or similar networks on the data link layer (L2) is done by a network bridge - you extract relevant data from an ingress frame (esp. source and destination MAC addresses), create a new frame for egress and copy the relevant data into it.
A bridge also examines each frame's source MAC address to learn where each node is located, so it only copies a frame to the other side when its destination is located there.
However, a router works on the network layer (L3): it forwards by IP destination address between IP networks/subnets. It uses data link layer (L2) encapsulation for reaching the next hop but doesn't convert anything. (It removes the encapsulating frame from a received packet, decides where to forward the packet, and then creates a new frame for that packet.)
You might be referring to a consumer-grade Wi-Fi router which effectively contains a NAT router, an Ethernet switch, a wireless access point (mostly bridged), DHCP and DNS servers, etc, blurring the distinction between all those functions.
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Install ali_jstorm
You can use ali_jstorm like any standard Java library. Please include the the jar files in your classpath. You can also use any IDE and you can run and debug the ali_jstorm component as you would do with any other Java program. Best practice is to use a build tool that supports dependency management such as Maven or Gradle. For Maven installation, please refer maven.apache.org. For Gradle installation, please refer gradle.org .
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