1. Usually this indicates that the IRIS is sending an incomplete certificate chain
2. The fact that you can access IRIS SMP has nothing to do with the outgoing HTTPS request, which I assume you do with %Net.HttpRequest and using the SSL property that match the SSL config
3. I recommend accessing the  https://myserver.com/api/gap/... from a browser and to check the certificate chain. Usually you will see 3 certificates (root CA, intermediate authority, the certificate itself) - you should put all those certificates (one after the other) in the PEM file that is configured in the SSL config in IRIS. Depending on the CA (which might be public, or company self-generated) you need to ask your sys admin 

Hello Malcolm,

You should consider using a VIP (Virtual IP) to let users connect to the current primary regardless of a mirror switch.

Usually, the arbiter machine, does not require IRIS to be installed, only the ISCAgent service, but if you have IRIS there with a license server than you lose the HA for licensing (in case arbiter machine is down).

Very good article Ashok!

If someone is going to calculate age in a production system, one should divide by 365.25 (to take into consideration leap years)

As Alexey said, the issue could be with code, not ECP (as usually ECP is backward compatible)
Make sure that code on app. servers in not mapped (no routine, package mapping) to a remote DB (on database server) - all code should be local to app. server

If your 3 app. servers are identical (for HA, LB reasons) then if you can disable access to 1 app. server and still working with other 2 - it will give you an option to to the app. servers one by one without downtime.

Another issue to concern is cached queries - on such upgrades its good to have all cached queries "un-freeze" to make sure all are compiled.
 

You can call directly to: Do BACK^%ETN it will save the $ZE + the stack. (LOG is also calling this one)

try $GET(%Request.Data("action",1))
Don't forget that you need to have the <input...> in a <form...> ... </form>

Hello Norman,

1. to build a sync mirror with the server, then you can "set no failover" on primary" and "play" withe the backup, you could take IRIS down in any time on the backup, it will re-sync when its up again

2. O/S defragmentation - either by O/S tool, or to copy the DB to a new clean disk

3. Internal defragmentation - there are some options:
A) to copy all data with GBLOCKCOPY to a new DB, with 1 process, to keep data as sequential as possible (will take a lot of time)
B) to use the internal defragmentation tool (will need 2 x space on that DB) then compact globals

4. In general, its a good practice to split indices to a different DB (and use mapping) since the data ("D" globals) are usually not getting so fragmented over time. This will also help on future defragmentation, compact globals, DB "shrink" and other maintenance on less volume 

Hello Alex,

I would suggest using MONLBL with all measures, to better understand any "bottlenecks" in code, memory issues or global access. In parallel, to monitor the VM to see if we hit CPU, disk I/O or memory thresholds there.
it might be that there are some "internal" functions that can be optimized or written definitely to speed up code.
I recommend that you open a WRC, since they have good tools to analyze almost every aspect of IRIS

Ashok,
I recommend that You have:
Set sc = workMgr.Queue("..Cleanup",QueueId)
and also:
Set sc = workMgr.WaitForComplete() 
Do workMgr.Clear()
All this will ensure a relegable and smooth completion of the queue manager.
We never used any hung when adding tasks into the queue.

Hi Ashok,

For the queue manager to recognize a proper completion of any code, it should be defined as a function.
If you test the sc for subr1 you will see a <PARAMETER> error. This is why the () is required.
It is better to have a quit $$$OK (or Quit 1) at the end, but this is not mandatory.

Very nice article.

Notice that your function SendDataStream() will not work for $Length(stream)>$$$MaxString
For this, you will need to split parts at sending, mark with an index and rebuild them on the reviver side, according to the index.

Some additional notes:

1. If you have many changes (variations) in query structure (e.g. using different column names, or different conditions on the WHERE clause) dynamic SQL is the choice. However, if your queries do not change in structure, only parameters than embedded SQL will be a better choice (e.g. select id for ref.table where name='name')

2. Embedded SQL build the cached query ONCE while you compile, embedded SQL build and compile a cached query every time your SQL structure changes.

2. Speed of dynamic SQL will be identical to embedded SQL (over time) since most of the possible SQL combinations will have cached queries in place - each time you compile a class/table, its "cached queries" are purged (so expect to have slight degradation after releases or changes in class/table)

 3. In case you can use embedded SQL consider giving your client access to a VIEW or a SP (instead of doing SQL against the original table). This way changes you do in class/table will not affect the client

4. As mentioned, security is very important to notice: if you intend to let the client send & execute (dynamically) any SQL, try to limit this for a specific table and sanitize the input to avoid potential "SQL injection" (using s SP with parameter is a good way to secure your backend)

Sets to a global with or without PC, single of multiple on 1 set command or using execute are relatively easy to find. The issue comes with indirections (@) - for that I recommend writing code that will do the searches (a real cross referencing). Over time, this code can be improved.

Another option is using visual studio code where you have an option to search with regex. which will let you find most of the easy places.

I recommend using visual studio code (vs-code) where you can search with regex. searching. Consider also seqdhing for 0-n while spaces to elimnate all spaces, tabs etc.
for example: a reference to a global could be:
set ^global( ... )= 
s ^global( ... )=
s:cond ^global( ... )=

If combined with other commands: then you should search for the comma (,) e.g.
set var=someting,^global( ...)=
 

However, use of indirection is very complex to find... (you need to skip 0-n of any characters including new lines between the set and the use of @)

1. Sound a perfect candidate for the InterSystems Ideas portal, to be able to do searches inside streams.
2. Another option:  you could use request/response messages that stores in normal properties (e.g. Extends Ens.Request or Ens.Response), you could convert those properties back to JSON or (compressed) stream at the BS level (after the response), so all your messages inside Ensemble could be searchable.

Hello Frank,

You can correlate the pid in O/S with the pid in Cache processes (in management portal). there you can see which namespace this pid is running in Cache. You can also have more information for that component: last line in source code, last global reference, if there are any locks might give you a good clue what this component is doing. 
If you are using ensemble, you can match the same pid to an ensemble job

Hello Gabriel,

It seems that updates to the other database (PostgreSQL) need to be "close to real-time," though a slight delay is acceptable. What matters most to you is ensuring stability and preventing any loss of updates.

I would consider the following:
1. Using the "SQL Gateway Connection" capability to connect remote tables directly to Cache. The benefit is that you have all logic on Cache side (having a remote REST/API will need also some remote logic to return the status of the operation in case of local updates failures)
2. Loosely coupling the local updates (Cache) with the remote updates:
a. Create a "staging area" (which could be a global or a class/table) to hold all updates to the remote table. These updates will be set by a trigger, ensuring that updating the local object/table in Cache is not delayed by updates to the remote database, The staging area delete its entries only on successful update (when failing they will be kept) - so you might need a monitor process to alert when the staging area is cleaning (e.g. remote DB is down, or network issues)
b. Use a separate (dependent) component to handle the updates. If you have interoperability (Ensemble), this might be easier to implement. However, it’s not mandatory; you could also use a background job (or a task) to periodically scan the "staging area" and perform the updates  
 

to be able to handle endStr in any length you should have:
S value = $E(text, start, end-$L(endStr)-1)

VS-Code will not delete on server. you need either to do that from studio, or use the d $System.OBJ.Delete() on terminal