Setting the TZ Environment Variable on Linux

The Update Checklist for v2015.1 recommends setting the TZ environment variable on Linux platforms and points to the manpage for tzset. This is recommended to improve the performance of Cache’s time-related functions. You can find out more about this here:

https://community.intersystems.com/post/linux-tz-environment-variable-not-being-set-and-impact-caché

The manpage on my CentOS 7 test system (RHEL 6 says the same) has this to say:

“The tzset() function initializes the tzname variable from the TZ  environment  variable.   This function is automatically called by the other time conversion functions that depend on the timezone.”

So how do you set TZ? How does it affect the time on a Linux server? Let’s see what we can learn

** Revised Feb-12, 2018

While this article is about InterSystems IRIS, it also applies to Caché, Ensemble, and HealthShare distributions.

Introduction

Memory is managed in pages.  The default page size is 4KB on Linux systems.  Red Hat Enterprise Linux 6, SUSE Linux Enterprise Server 11, and Oracle Linux 6 introduced a method to provide an increased page size in 2MB or 1GB sizes depending on system configuration know as HugePages.

At first HugePages required to be assigned at boot time, and if not managed or calculated appropriately could result in wasted resources.  As a result various Linux distributions introduced Transparent HugePages with the 2.6.38 kernel as enabled by default.  This was meant as a means to automate creating, managing, and using HugePages.  Prior kernel versions may have this feature as well however may not be marked as [always] and potentially set to [madvise].  

Transparent Huge Pages (THP) is a Linux memory management system that reduces the overhead of Translation Lookaside Buffer (TLB) lookups on machines with large amounts of memory by using larger memory pages.  However in current Linux releases THP can only map individual process heap and stack space.

I have an application using examples from the lottery example in samples name space how do I create a dynamically link based on the data displayed to add a record id to the link

the idea is to loop over the records displays fields and link to edit the shown data at the end of the record in a table format

I have a query string that I am creating programmatically, based on some user inputs.  The user might search on 5 fields, or 8 fields, or no fields.

In my sql statment, some of these fields require parameters in the %Execute statement.

For example:

if user picks lastname, sql = "select * from person where lastname = ?"

if user also picks age, sql = "select * from person where lastname=? and age > ?"

I then have these lines of code to create my result set:

set statement = %SQL.Statement

statement.%Prepare

resultset = statement.%Execute(param1, param2)

-- but it might be 

resultset = statement.%execute(param1)

How can I pass a variable number of parameters  when I don't know how many the user will pick to filter the search?  I need some kind of parameter object? Or will indiraction work? Something with $lists? %ListOfDataTypes?

parameterObject.Insert(param1

I have two classes

Date range queries going too slow for you?  SQL Performance got you down?  I have one weird trick that might just help you out! (SQL Developers hate this!)*

If you have a class that records timestamps when the data is added, then that data will be in sequence with your IDKEY values - that is, TimeStamp₁ < TimeStamp₂ if and only if ID₁ < ID₂ for all IDs and TimeStamp values in table - then you can use this knowledge to increase performance for queries against TimeStamp ranges.  Consider the following table

Hi all. Today we are going to use k-means algorithm on the Iris Dataset.

Note: I have done the following on Ubuntu 18.04, Apache Zeppelin 0.8.0, python 3.6.5.

Introduction

K-Means is one of the simplest unsupervised learning algorithms that solves the clustering problem. It groups all the objects in such a way that objects in the same group (group is a cluster) are more similar (in some sense) to each other than to those in other groups. For example, assume you have an image with a red ball on the green grass. K-Means will split all pixels into two clusters. The first cluster will contain the pixels of the ball, the second cluster will contain the pixels of the grass

Hello everyone,

i am in process of changing our authentication method, so we can integrate our AD authentication in our programs. At the moment i am using they %SYS.LDAP object, and trying to use the .Bind() method with the user information to authenticate. This seems to work without issues, but here the problems start.

When i flag a user 'Change password on next logon' in our Active Directory, the Bind fails with a status error: "Invalid Credentials". To make sure the user who logged in is in fact the user to change the password. I still need to check if this user entered the correct current login information.

Checking the fields 'badPwdCount' or 'badPasswordTime' does not help since they are not filled after a failed .Bind() it seems.

Anyone has experience with this issue and knows how to work around the change password issue?

Thank you guys in advance!

Thomas

Hello All,

I have been associated with Intersystems technologies for over a decade working on Cache, Zen, Ensemble etc.

This is a very niche field and a lovely community. I wanted to extend my hands to connect with people who are of same field or related to it.

Here is my linkedin profile. Pls feel free to send me an invite or drop me a message

https://www.linkedin.com/in/vneerav/

We can load a CCDA xml document into SDA3 object.

Once parsing SDA3 object, how do we determine from which XPATH from CCDA the specific SDA3 elements were mapped to.

Is there any way?

I am having an intermittent issue that when I make a call to MSSQL from a BPL that the response does not come back in the amount of time required. Since the call from the BPL is synchronous I tried changing the timeout to 60 but it has not helped (see below). Is there anyway to guarantee that the call waits long enough for a response before continuing on?

Thanks

Scott Roth

Hi All,
 How to create Https request with Negotiate,NTLM Authentication in cache using %Net.HttpRequest package.
 I tried with basic authentication it is throwing >401 - Unauthorized: Access is denied due to invalid credentials.
 
 can anyone please guide me 
 
 Many Thanks !!
 Vicky

We have a large number of processes and operations being applied to outbound HL7 messages from our PAS.

If I select a message, and open its visual trace, I see the service, as well as all processes, and operations. 

My debugging is often about a new operation, and I don't need to see all the other operations that are in functioning as desired.

Is is possible to configure Visual Trace to only show specific services,processes and operation?  Or is is possible to see a trace from the perspective of a particular operation, showing only (service,process&Operation) columns in the trace that pertain to that operation, or the resulting message?

Kind Regards,

Stephen

Hi , i have a JSON record as follow {value1,value2, value3}

i want to write my switch statement in this form:

<switch> my value
<case> value1</case>
<case>value2</case>
<case>value3</case>
​</switch>

is there any possibility to extract values from JSON record and put them in a  switch statement?

thank's