Apache Storm Multilang: Purpose of ReadTasksIds -

-

i have been attempting use storm's multilang protocol project. i've read through protocol , part makes sense. looking on python multilang source code i've noticed in emit method after emitting tuple, calls readtaskids() method. 

def emit(*args, **kwargs):     __emit(*args, **kwargs)     return readtaskids()

on concepts page, mentions using directgrouping() able send output specific task. , lines 124-129 of jsonserializer (which handles multilang communication) it's checking see if "need_task_ids" field present , not send taskids if it's defined false in json.

so i'm wondering if can explain/confirm me why storm needs tasksids? there's nothing in multilang protocol mentions it. use case of wanting send tuples specific task using directgrouping()? or there benefit having it? adding "need_task_ids" field in json pretty easy stop happening (if understand correctly), don't know if there downsides in doing that?

i not familiar multilang protocol. however, explanation meets experience in using storm's low level java api. in api, either specify task-ids in case of direct stream or no task-ids in case of other groupings (eg, shuffle, field, all). thus, claim own explanation correct. know internal clojure code same thing: checks if task ids provided. if not, looks specified connection pattern, computes task-ids, , returns them user code after sending tuples.


Comments

Post a Comment

Popular posts from this blog

html - Firefox flex bug applied to buttons? -

-
i'm trying apply flex button on firefox i'm having problem on chrome doesn't happens. this css: .button { display: inline-flex; align-items: center; } as can see in fiddle, "caret" word moved new line, happens if element <button> tag, <div> works expected. http://codepen.io/anon/pen/xblmgx is firefox bug or there css i'm missing? nevermind, looks "mr firefox" doesn't idea... <button> not implementable (by browsers) in pure css, bit of black box, perspective of css. means don't react in same way e.g. <div> would. this isn't specific flexbox -- e.g. don't render scrollbars if put "overflow:scroll" on button, , don't render table if put "display:table" on it. stepping further, isn't specific <button> . consider <fieldset> , <table> have special rendering behavior: data:text/html,<fieldset style="d
Read more

html - Missing border-right in select on Firefox -

-
Image
when put select div width , padding-left, options have no border on right. more, happend if select have width 118px , parent have 15px of padding left! have idea, going on? my code: <!doctype html> <html> <head lang="en"> </head> <body> <div style="width: 1000px; padding-left: 15px;"> <select style="width: 118px;"> <option>a</option> <option>b</option> <option>c</option> </select> </div> </body> </html> and result: here plunker: click it happend on firefox on windows. tested on 40.0.2 version -webkit-box-sizing: border-box; -moz-box-sizing: border-box; -ms-box-sizing: border-box; box-sizing: border-box; source: https://stackoverflow.com/a/11390432/4431269 source of problem: https://bugzilla.mozilla.org/show_bug.cgi?id=924068 and use of google ! edit: (source of problem, explained) after rea
Read more

c# - two queries in same method -

-
i trying execute 2 queries in same method gives me exception. can red of exception declaring new command there way use same command? string id="hi"; connection.open(); oledbcommand command1 = new oledbcommand(); command1.connection = connection; string query1 = "select * products category='" + combobox1.text + "' , subcategory = '" + combobox2.text + "' , sizes='" + combobox3.text + "'"; command1.commandtext = query1; oledbdatareader reader = command1.executereader(); while (reader.read()) { id = reader[0].tostring(); } textbox1.text = id; string query = "insert category_in (category_id,amount,amount_in) values ('"+ id+"' ,500,300)"; command1.commandtext = query; command1.executenonquery(); messagebox.show("saved"); connection.close();
Read more