源码分析Kafka 消息拉取流程(文末两张流程图)

扶醉桌前 提交于 2019-12-12 22:14:46
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 本节重点讨论 Kafka 的消息拉起流程。 @ TOC 1、KafkaConsumer poll 详解 消息拉起主要入口为:KafkaConsumer#poll方法,其声明如下: public ConsumerRecords<k, v> poll(final Duration timeout) { // [@1]( return poll(time.timer(timeout), true); // @2 } 代码@1:参数为超时时间,使用 java 的 Duration 来定义。 代码@2:调用内部的 poll 方法。 KafkaConsumer#poll private ConsumerRecords<k, v> poll(final Timer timer, final boolean includeMetadataInTimeout) { // [@1]( acquireAndEnsureOpen(); // @2 try { if (this.subscriptions.hasNoSubscriptionOrUserAssignment()) { // [@3](https://my

Is there a way to do lookups on default record values?

左心房为你撑大大i 提交于 2019-12-12 10:13:17
问题 Given a record -record(something, {id :: integer(), name :: string(), email = undefined :: string() | undefined}). Is there a way to get the default values for the fields, in this example getting the fact that defaults to undefined? 回答1: Records are syntactic sugar in Erlang , expanded by the compiler. The following solution, suggested by @Dmitry, works, but the compiler will not optimize it away unless you pass +inline, since the trick here is to really create a record: g()

Delphi Saving/Loading Dynamic Arrays Failed

不打扰是莪最后的温柔 提交于 2019-12-12 08:59:05
问题 I think this will look like ' do my homework ' kind of a question, but I'm still at the ' copy code, use it and try to understand it ' phase, and this is the most active thing I know of for posting questions of this theme. I have a record: type Card = record Name: string; Up,Right,Left,Down,Mark: Single; IDNumber: Integer; end; And array of that record: var ArrayCard: array of Card; And I wanted to know how can a dynamic array of this kind be stored/loaded to/from a file. Tried using this

DNS records to point to another domain

喜欢而已 提交于 2019-12-12 06:37:12
问题 Usually I would upload a .htaccess to redirect a domain to another domain. But can something be done with the DNS settings when there is no hosting set up, to point one domain to another in a similar fashion to a redirect? -> 回答1: Your domain can just have a CNAME type, redirecting to your other domain. 回答2: There are many ways to do this. One is to set up a virtual domainA server on the domainB box. Another is to use a web forward in your domainA DNS record.

cakephp habtm join issue

房东的猫 提交于 2019-12-12 06:05:49
问题 I have table structure like below: events (boxing, sparring etc) competitors (users who are participating into diff events) events_competitors (every competitor's selected events will go here) Now what i want is, as per my match schedules i want to find competitors from schedules tables, where each competitors will be matching with events they have selected at registration time. I'm using a find query something like this: $matchdivisions = $this->Competitor->find("all" , array( 'conditions' =

Show number of factories behind categories in sidebar. codeigniter

巧了我就是萌 提交于 2019-12-12 03:55:59
问题 I have a sidebar with categories. when i click on one categorie it shows me the factories who are located in that category. I did this using joins in codeigniter. Now i want to show how much factories are in a category. so for example: Categories. Cars (2) Books (7) Animals (45) So it simple has to show how much factories have that specific category. i tried to do a simple count_all_results but then i get the total count of factories. but i want them to count by the specific id of categories.

Get all Django records created since last login

牧云@^-^@ 提交于 2019-12-12 03:23:37
问题 Using Django models, is there a filter I can use to select all records created after a certain date? I'm not sure what syntax or filter I should use to get all records newer than my last_login. I wouldn't mind doing it with a Q advanced query, but the simpler the better! 回答1: Actually, you don't need the current datetime if you want to select all records created after a certain date. Just use a filter with a lookup like: field_date__gte=last_login. It's not necessary to use range here. For

Find duplicate columns that have values that end with same last four digits - SQL

╄→гoц情女王★ 提交于 2019-12-11 20:09:30
问题 I need a query that will search for all records in a table and return only the ones that have 2 or more values that end with same 4 digits, but i dont have specific four digits i can give you, i just need it to find everything that has more than one value that ends the same. eg. table has: person_number------------name ============================== 1234567------------------john 00004567-----------------mark 9999999------------------mike 0009999------------------lidia 10101010----------------

Select records based on the specific index string value and then remove subsequent fields by python

主宰稳场 提交于 2019-12-11 20:06:10
问题 I have a .csv file named file01.csv that contains many records. Some records are required and some are not. I find that the required records has a string variable “Mi”, but it is not exist into the unnecessary records. So, I want to select the required records based on string value “Mi” in the field for every records. Finally I want to delete the subsequent fields of each record from the field that contains value “Mi”. Any suggestion and advice is appreciated. Optional: In addition, I want to

Creating an Interactive Multi Field Search Bar in MS-ACCESS

一曲冷凌霜 提交于 2019-12-11 15:39:06
问题 I know this is probably a simple thing I'm missing, but I'm hoping you all can help. I'm trying to add a textbox to my form that allows users to type in search criteria and have the query filter the records to only display those that qualify. The trick is I want the user to be able to type in info and have it check all the fields of the form and return records for any that are valid. I set up a query with the fields that I want checked and I watched a few tutorials on setting criteria, but