Shared data - concurrent access

Entity beans are best used when shared data is being concurrently accessed.
Could you please clarify this statement . How does it different than shared data - concurrent access by jdbc DAO class ?

jverd wrote:
I have no idea what you're asking. I cannot provide clarification until you do.Ok. let me explain further. my question is , is it a good idea that whenever we need shared concurrent data access in a application Entity bean is the best ? Why? does it really outsmart the jdbc DAO access methodology whenever it comes to the realm of shared concurrent data access ?
For example: I can think of a system e.g online auction house application. This needs concurrent shared data access ..right ?
Do you think use of Entity bean is best here instead of jdbc DAO access methodology ? Why ?

Similar Messages

How to synchronize concurrent access to static data in ABAP Objects

Hi,
1) First of all I mwould like to know the scope of static (class-data) data of an ABAP Objects Class: If changing a static data variable is that change visible to all concurrent processes in the same Application Server?
2) If that is the case. How can concurrent access to such data (that can be shared between many processes) be controlled. In C one could use semaphores and in Java Synchronized methods and the monitor concept. But what controls are available in ABAP for controlling concurrent access to in-memory data?
Many thanks for your help!
Regards,
Christian

Hello Christian
Here is an example that shows that the static attributes of a class are not shared between two reports that are linked via SUBMIT statement.
*& Report ZUS_SDN_OO_STATIC_ATTRIBUTES
REPORT zus_sdn_oo_static_attributes.
DATA:
gt_list TYPE STANDARD TABLE OF abaplist,
go_static TYPE REF TO zcl_sdn_static_attributes.
* CONSTRUCTOR method of class ZCL_SDN_STATIC_ATTRIBUTES:
**METHOD constructor.
*** define local data
** DATA:
** ld_msg TYPE bapi_msg.
** ADD id_count TO md_count.
**ENDMETHOD.
* Static public attribute MD_COUNT (type i), initial value = 1
PARAMETERS:
p_called(1) TYPE c DEFAULT ' ' NO-DISPLAY.
START-OF-SELECTION.
* Initial state of static attribute:
* zcl_sdn_static_attributes=>md_count = 0
syst-index = 0.
WRITE: / syst-index, '. object: static counter=',
 zcl_sdn_static_attributes=>md_count.
DO 5 TIMES.
* Every time sy-index is added to md_count
 CREATE OBJECT go_static
 EXPORTING
 id_count = syst-index.
 WRITE: / syst-index, '. object: static counter=',
 zcl_sdn_static_attributes=>md_count.
* After the 3rd round we start the report again (via SUBMIT)
* and return the result via list memory.
* If the value of the static attribute is not reset we would
* start with initial value of md_count = 7 (1+1+2+3).
 IF ( p_called = ' ' AND
 syst-index = 3 ).
 SUBMIT zus_sdn_oo_static_attributes EXPORTING LIST TO MEMORY
 WITH p_called = 'X'
 AND RETURN.
 CALL FUNCTION 'LIST_FROM_MEMORY'
 TABLES
 listobject = gt_list
 EXCEPTIONS
 not_found = 1
 OTHERS = 2.
 IF sy-subrc <> 0.
* MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
* WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
 ENDIF.
 CALL FUNCTION 'DISPLAY_LIST'
* EXPORTING
* FULLSCREEN =
* CALLER_HANDLES_EVENTS =
* STARTING_X = 10
* STARTING_Y = 10
* ENDING_X = 60
* ENDING_Y = 20
* IMPORTING
* USER_COMMAND =
 TABLES
 listobject = gt_list
 EXCEPTIONS
 empty_list = 1
 OTHERS = 2.
 IF sy-subrc <> 0.
* MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
* WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
 ENDIF.
 ENDIF.
ENDDO.
* Result: in the 2nd run of the report (via SUBMIT) we get
* the same values for the static counter.
END-OF-SELECTION.
Regards
Uwe

SRS Browser Role Cannot Access Shared Data Sources

I've created some reports using VS and shared data sources and deployed. I can run reports (I'm a domain admin), but users I've given system administrator roles within SRS cannot access shared data sources. However, if I embed the data source, everything
is fine. I'm pulling data from three different servers, so the shared data sources are somewhat important. I'm using SQL Native userid/passwords not windows authentication. Anybody got any ideas? I'm new to SRS. Thanks.

Hi Janetb,
I’m confused about the meaning of “cannot access shared data sources”. Are you saying the user cannot see the Shared Data Sources in Report Server, but he can render the report well? Or the user cannot render the report well because he have no permission
to access shared data sources?
If in this first scenario, means that the role of the user have no permission to View data sources. To fix this issue, we can add View data sources task to the current role in SQL Server Management Studio.
If in the second scenario, it is so strange. In my test, I add Browser role of the report to one user which has no permission to access the shared data sources, but he can render the report which retrieve data from the shared data sources very well.
To troubleshooting this issue more efficiently, could you tell us the scenario you occurred and the error message you received? So that we can make further analysis and help you out.
Thanks,
Katherine Xiong
Katherine Xiong
TechNet Community Support

Shared Data Partition + Lion + Snow Leopard - What files go where?

I have partitioned my new internal drive into 3 (which is currently in a enclosure).
The 1st Partition reserved for Lion
The 2nd for reserved Snow Leopard
And the 3rd reserved for a shared Data parition
I'm not enirely sure how to divde up the files. What should be put on the Data parition?
And how to direct each OS parition to access the shared data partition?
I would appreciate advice and example(s). Detailed information is always welcome.
Thank you.

darkhorse85 wrote:
It would excellent if you would could me about other programs such as Mail which would suffer releated issues.
I really don't know, and don't know if there's a list anywhere of Mac apps. Mail seems to change with every release (and even some "point" updates). I think Calendar is one, too.
This list of 3rd-party apps is unofficial, but seems pretty reliable as far as what will run where: http://roaringapps.com/apps:table
As you'll see, it's mostly geared towards Lion vs. Mountain Lion (and in a few months, will be Mountain Lion and Mavericks).
You'll probably have to use some trial-and-error, and/or contact the makers of the apps you use.
I am not familiar with using any kind of software as a Virtual Machine how would this work?
I'm not very familiar with it, but you install 3rd-party software that lets you run one OS within a different one, rather than having to boot into one or the other. Basically, it puts a Virtual Machine folder containing one whole OS installation on the disk of another; it runs concurrently with the other OS, in a separate window (or multiple windows for different apps, I think). There are some downsides, especially performance, but a lot of folks do it, usually to run Windows, but some to run Snow Leopard on Lion or Mountain Lion. There may be some restrictions on the Snow Leopard license, too -- Apple didn't allow that for OSX at all for a long time, except for the Server product. I don't know what the rules are now.
Parallels and VMware are two I see mentioned often. I seem to recall reading about a free one, but as it's pretty complex software, I'm a bit skeptical.
I don't know where else to point you, but that should get you started on research. Look for those apps and/or Virtualization Software to find more.
Good luck!

ADF selectOneChoice - concurrent access

Hello,
I have an ADF aplication (i use jdev 11.1.1.2.0) that has a page with a richTable and a form that populate its fields when a row for the table is selected. The form can be also submited when a user complete its own details.
My problem apears when are more users accessing the page.
The selected index of the af:selectedOneChoice shared its value between the users sessions?
Thank you

Hi,
That cannot be the problem, each selectOneChoice is a separate object with separate values.
Is the data you display based on a table? This data however is shared so concurrent updates etc are a more likely cause I think.
But really, some more info about the actual problem would be helpful
-Anton

Working with multiple users and computers, but shared data

Sorry if this is posted in a poor place, I'm not sure where the best place is. This is sort of a general questions.
For a long time, my wife and I have had either one computer, or two machines but one has definitely been just a terminal. We've basically set up all of our data to be one one primary machine, and if we want to view/edit that data we have to use that machine.
We just got a new MacBook Pro and I would like to be able to use two machines as equals. Sadly, this idea of multiple computers, with two users and some shared data is really giving me difficulty. I was wondering if anyone has any suggestions on how to best manage things like:
Synchronizing portions of our contact list (We share about 50% of the combined library -- we don't have to share all though).
How to manage iPhoto so that we can each have access to the photos. As an added difficulty (or maybe this is easier?) my Wife just wants to have access to the pictures for viewing and sharing on Facebook/Picassa/etc. I am the only one who wants to edit, correct and cull our library. That said, I always edit when I first put the data on the machine, and almost never again; so it would be fine to have one (or both accounts) set up as view only for the iPhoto data.
How to manage iTunes so that we can each have access to the music. As a super awesome bonus, it would be great if we could have three libraries: His, Hers and Shared. Maybe as much as 30% of our music library is similar, the rest just gets in the way.
What is the best solution people have found for calendars? (I'm thinking two separate calendars, and we each subscribe to each others iCal feed)
Mail.app and bookmark synching is not really a problem for us.
Two extra points:
* One machine is portable, and the other isn't. Ideally, when the laptop is out of the house, both machines should still have reasonable access to the shared data. That is: Just dumping things in the shared folder won't work because when the laptop is out of the house we will be disconnected from the source data.
* We just got a second iPhone. This means that both of us will be taking photos/video separately and trying to synch back to the master data store.
* Basically, I'm trying to minimize data duplication as much as possible, and just synchronize the systems to each other.
Thanks a ton in advance. If anyone has any suggestions at all, I would love to hear them. Including "This is in the wrong forum, go ask here instead..."

So you have a desktop Mac and a laptop Mac, right? Two user accounts (and a third admin account) on each computer, right?
I profess that I haven't tried this, but here is how I would approach your problem:
Sharing Music and Photos between multiple user accounts on the same computer:
See if http://forums.macrumors.com/showthread.php?t=194992 and http://forums.macrumors.com/showthread.php?t=510993 provide any useful information to assist you in this endeavor.
Sharing across multiple computers:
Turn on file sharing on the Desktop (System Preferences > Sharing). Now you can mount the Desktop as an external drive on the laptop's Desktop. Copy the music and photo folders across. Will take awhile to do the first time. Then, for future use, get a copy of the donationware CarbonCopyCloner or equivalent. You can use CCC to selectively sync specific folders from one computer to the other. There may be a hassle with digital copyright issues on music and movies, though.
Calendars:
As you have suggested yourself, publishing yours and subscribing to hers is probably the best way to do it, on the same computer. Across computers, syncing with CCC or equivalent would probably be the way to go.

Caching user shared data in WebDynPro (i.e. applicationBean)

Hi,
I'd like to know if there's a standard way to cache/access user shared data on the J2EE engine running my WebDynPro app.
I need to do that because Bapis call in our application are expensive. Thus we want to minimize them. It would be impossible to rewrite the whole backend, because we're migrating from an existing application.
I thought about sharing through a database local to the J2EE engine, or file sharing through a lock. But I bet these options are likely to hinder me than anything else.
Does anybody has a suggestion?
Thanks in advance,
Alexis Trudeau

Indeed, my explanations are a bit misleading. According to your definition, I'm talking about shared data.
For example, in my application we have user profiles. Each user has a subset of these profiles.
Usually, these profiles are only modified during the deployment stage on the client's infrastructure.
Once settled, these profiles are static during production. In that case, I'd rather fetch all the profile once, and work with them locally on the J2EE engine instead of fetching them each time a user is authentified.
Do you have further suggestions?
P.S. Yes, I do use NetWeaver wizard to create Adaptive RFC Model

Best practice for sharing data with model window

Hi team,
what would the best practice for sharing data with a modal
window be ? I use a modal window to display record details from a
record list, but i am not quite sure how to access the data from
the components in the main application in the modal window.
Any hints would be welcome
Best
Frank

Pass a reference to the parent into the modal popup. Then you
can reference anything in the parent scope.
I haven't done this i 2.0 yet so I can't give you code. I'll
post if I do.
Oh, also, you can reference the parent using parentDocument.
So in the popup you could do:
parentDocument.myPublicVariable = "whatever";
Tracy

Shared data plans not available when upgrading to iphone5

Last night I upgraded two 3G smartphone and a basic phone to iphone5's for all three of us. Currently on shared unlimited data/text and 1400 min. shared voice. The ordering process would not allow me to select the new tiered shared data plans. It only made individual data plans available and these were combined with aspects of the old plan ($10/month access fee, 1400 shared minutes, etc.). My chat with customer rep "Sunny" was inconclusive as he/she only stated that I couldn't order new phones and the new shared data plan all at once, but would have to order the phones and then switch the data plan after phones are activated (shipping 10/26).
Anybody else gone through this frustrating process? Should I just wait until the iphone5's show up and try to switch plans then? Or should I sit through the 30-45 minutes customer service hold time and try to resolve this now?
Thanks.
Ken

Ordering online usually doesn't allow for more than one change to the account at a time. You have to complete the upgrade in one step. Then once that is finalized in the account, then you can change to the Share Everything plans.
You might be able to complete both changes at same time if you ordered through customer service via phone.

Issue with User Variable Due Shared Member Security Access

Hi All,
One of my client is using User variable in data form to define POV.
Now if user has access to 2 member in the Dimension, he should able to see 2 member when he try to assign the value to this "user variable"
but he can see some of the parent member name ,this parent name has only one child which is a shared member of the 2 base member for which he has access.
For Example:
Entity Dimension:
E1 (user has access)
E2
E3(user has access)
E4
Alt_Entity
Alt_Entity1E1 (sharedmember)
Alt_Entity2E2 (sharedmember)
Alt_Entity3E3 (sharedmember)
Alt_Entity4E4 (sharedmember)
User is able to see below members, when he try to assign value
E1 (user has access)
E3(user has access)
Alt_Entity1
Alt_Entity3
Now if I add another member under this parent, than user are unable to see this parent member.
For Example:
Entity Dimension:
E1 (user has access)
E2
E3(user has access)
E4
Alt_Entity
Alt_Entity1
E1 (sharedmember)
E2 (sharedmember)
Alt_Entity2E2 (sharedmember)
Alt_Entity3
E3 (sharedmember)
E2 (sharedmember)
Alt_Entity4E4 (sharedmember)
User is able to see below members, when he try to assign value
E1 (user has access)
E3(user has access)
Any idea?

Sorry, but actually its the parent that needs tagging with "Never Share", not the level 0 member, so Alt_Entity1 and Alt_Entity2 etc, see Essbase DBA guide
understanding Implied
Sharing
The shared member property defines a shared data relationship explicitly. Some
members are shared even if you do not explicitly set them as shared. These
members are said to be implied shared members.
If you do not want a member to be shared implicitly, mark the parent as Never Share so
that the data is duplicated, and is not shared. See Understanding Shared Members for an
explanation of how shared members work.
So in the example above
Entity Dimension:
E1 (user has access)
E2
E3(user has access)
E4
Alt_Entity
Alt_Entity1 - Set to "Never Share"E1 (sharedmember)
Alt_Entity2E2 (sharedmember)
Alt_Entity3 - Set to "Never Share"E3 (sharedmember)
Alt_Entity4E4 (sharedmember
Thanks
Anthony

Concurrent access in Diadem

How does Dia dem manages concurrent access?
If several network users each of them having a floating licence, want to access the same objects (datasets, reports, view layout), can they?
What happens if they want to load/delete/modify datasets located in the same folder?
And if they want to write on the same report?
Thanks

Hi condor31,
The only thing which is concurrent is the license file. The DIAdem installation is still local on the client computer, which means that client A's DIAdem is completely separate from client B's DIAdem, because the two DIAdems are running on completely different computers. So you don't have to worry about collisions at the REPORT object level at all. If DIAdem A and DIAdem B attempt to access or update the same external files (layout files, data files, etc.), then the usual file access rules apply. Both DIAdem A and DIAdem B can load the same layout or data file from computer C, say, and play with them back on computers A and B, respectively. If DIAdem A then overwrites the layout or data file on computer C with an updated version, DIAdem B doesn't notice, because DIAdem B has those files in memory on computer B. If DIAdem B subsequently overwrites the layout or data file on computer C, then DIAdem B wins and its version of the file is now on computer C, though DIAdem A doesn't know this has happened. If you want to protect a particular data or layout file, you can of course set its Windows read-write permissions to read-only, then neither DIAdem A nor DIAdem B will be able to change it, though they will be able to read it and use it and save the edited version to a new data or layout file.
The one exception to this is if DIAdem A and DIAdem B happen to register-load the same data file, then they each have an implicit link back to the data file on computer C, and neither will be able to change that data file, since register-loading opens the data file read-only and puts a lock on it so that no one can change it while you have it open, but this is a special case.
Brad Turpin
DIAdem Product Support Engineer
National Instruments

Dual-booting with other Linuxes; shared data partition

I've got two entirely-blank 320GB hard drives on my computer, and I'd like to dual-boot Arch and Debian on it (and potentially others later). How should I set up GRUB (or GRUB2-- the wiki says that it's a better option when dual booting with other distros) for each OS in order to have both of them able to boot, as well as retaining the capability of adding other distros? (Assuming that Arch's GRUB(2), not Debian's, will be installed to the MBR.)
In addition, I'd like to keep my config files and data separate (with a shared data partition on HD 2).
- What is the best way to set this up separately from the /home partition, i.e. mount /data on startup and be able to access it quickly from a filemanager or the commandline? I venture a guess that I'd edit /etc/fstab and add a symlink to /data within /home/USERNAME...
- What is the right size for the /home partition in this setup?
A tentative partition scheme is as follows (note that I have 4GB RAM, since that factors into swap size):
HD 1
4GB shared swap partition
256MB ext3 Arch /boot partition
20GB ext4 Arch / partition
? ext4 Arch /home partition *see note above*
256MB ext3 Debian /boot partition
20GB ext4 Debian / partition
? ext4 Debian /home partition *see note above*
(free space)
HD 2
320GB shared ext4 data partition
Last edited by DrKillPatient (2012-06-20 18:38:01)

Most of it is a matter of opinion I think, but since I have a similar setup I'll throw in my two cents.
DrKillPatient wrote:I've got two entirely-blank 320GB hard drives on my computer, and I'd like to dual-boot Arch and Debian on it (and potentially others later). How should I set up GRUB (or GRUB2-- the wiki says that it's a better option when dual booting with other distros) for each OS in order to have both of them able to boot, as well as retaining the capability of adding other distros? (Assuming that Arch's GRUB(2), not Debian's, will be installed to the MBR.)
I use GRUB (legacy). Adding a distro in the grub menu is just a matter of finding the kernel and initram image of the distro and adding an entry. OS's generally either have a fixed location/name for the kernel and image or have a fixed link, so there are no problems on updates. I really don't like GRUB 2 and don't see the point of using it unless you are using something exotic that GRUB doesn't support.
DrKillPatient wrote:I
In addition, I'd like to keep my config files and data separate (with a shared data partition on HD 2).
- What is the best way to set this up separately from the /home partition, i.e. mount /data on startup and be able to access it quickly from a filemanager or the commandline? I venture a guess that I'd edit /etc/fstab and add a symlink to /data within /home/USERNAME...
- What is the right size for the /home partition in this setup?
I just mount the data partition in /mnt/data and make symlinks from my home partition. In my case the data partition is ntfs, since I also use windows. My home partition contains 1.2 GB, of which 600 MB source code. So if you only keep configs in them it probably won't reach 1 GB.
DrKillPatient wrote:
I
A tentative partition scheme is as follows (note that I have 4GB RAM, since that factors into swap size):
HD 1
4GB shared swap partition
256MB ext3 Arch /boot partition
20GB ext4 Arch / partition
? ext4 Arch /home partition *see note above*
256MB ext3 Debian /boot partition
20GB ext4 Debian / partition
? ext4 Debian /home partition *see note above*
(free space)
HD 2
320GB shared ext4 data partition
In my opinion a seperate boot partition is only useful for the OS of which the bootloader is installed to the MBR.

How does the Concurrent Access License (CAL) work.

Description from Google: How does the Concurrent Access License (CAL) work? Xcelsius Engage Server CALs allow for concurrent live data updates inside Xcelsius dashboards. Every time an end-user triggers a Web service inside an Xcelsius dashboard to retrieve live data, a CAL is consumed for a period of 5 minutes. For that period, in a five CAL deployment for example, there will be only four CALs left for consumption. A five CAL deployment could support up to 25 users and additional CALs can be added to support a larger deployment.
My question is as follows:
How a five CAL deployment could support up to 25 users and what does it mean. In the first line it is saying that each CAL for a web service is consumed for a period of 5 minutes and how come it can support 25 users concurrently. Did it mean 25 web service connections inside a swf flash file or 25 different users to access a single web service through swf flash.

The "Set cost controls" concurrent program is used in R12 to mass update the cost control fields on item costs.
The cost control region is found by going to Cost management >Item costs > Item Costs
The concurrent program lets you specify which items /costs should be updated by using various parameters such as cost type, item range, category range etc.
And you can specify the source for the new cost control data and the new value for the fields.
Hope this answers your question,
Sandeep Gandhi

Advice pls. re. Users and Groups and shared Data

Before I get to concrete questions, I'd like to explain what I have in mind and would welcome suggestions; ie. is it reasonable or have I overlooked something easier or any pitfalls?
Basically, I've got 3 user accounts (not counting FTP, MySQL, etc) on my Powerbook, which are all mine, just represent different "personas" (private, work, music composition). I've had it like that for years and am perfectly happy. Eg. when I'm working I don't see a desktop cluttered with the latest junk I've downloaded and when I've got my music making hat on I open up iTunes and see my sample collection. So far so good!
But it does have some drawbacks of course, when it comes to sharing data accross accounts (email, contacts, calendar, passwords, etc). For most there's an individual and easy enough solution but I'd really like one single solution and not have to keep doing difference maintenance tasks on different files in different accounts. And just to further compound the issue, I'd really like to have all this "shared data" in one central location for easy sync with my XP box.
My idea is thus; a fourth virtual user (something like "me"), which doesn't appear in the login/user-switching menu, but whose home folder is simply a repository for all this shared stuff I'm talking about. Syncing with XP whould then be a breeze!
I'd then use aliases and/or symbolic links as appropriate, from my usual three accounts, for example, to a single Thunderbird profile or Calendars folder or whatever.
Finally, currently I've got all user accounts set up as admin accounts, mostly so they can all access each other's data. I don't like this though, from a security point of view and would prefer to assign them all to a (new) group "virtual-me", adding each user into this group.
Does all this sound reasonable?
Cheers,
Rich
BeigeG3 400/256/40 OS921, PismoG3 400/768/80 Mac OS X (10.3.9) Atari 1040 STe, 4Mb, 100Mb HD, Zip 100, 4x CD

have sorted it now, no need for a "virtual" user, just added a new group and shoved all the files I want to share accross accounts into a folder in /Users... as i suspected, I was thinking far too complicatedly

Two Firefox Private Browsing sessions are sharing data.

I launched Private Browsing Firefox session & logged in to gmail then, I launch another Private Browsing Firefox session. This time, again I visit gmail.com & I got logged in to my gmail inbox without authentication even though I am in two different Private Browsing sessions. Then, again, I launched 3rd Private Browsing Firefox session, this time I visit google.com & I can see my gmail ID on right hand top corner.
I have opted “Automatically start Firefox in Private Browsing” as I don’t want to let google search keep my search history.
It seems like Firefox do share cookies & other data in Private Browsing sessions. So how these sessions can be called Private Browsing if they are sharing data?
Note: I have tried “Start Private Browsing” manual command as well but found no difference in behavior.

Dump firefox and use the File->New Session option in Microsoft's IE browser. I am a software developer and from my personal experience I can say that firefox sucks, and is the least secure browser out there.
You'll find this out when someone hijacks your bank account after you've accessed it using firefox.

Shared data - concurrent access

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