Hello and welcome to the SAP HANA Academy.
The topic of this video tutorial series is SAP HANA Administration and in this video
we will take a look at the System Health Monitor.
This video has been recorded on release SAP HANA cockpit 2.0 SP08 from October 2018.
For earlier or later releases, please check the playlist on the SAP HANA Academy.
Hi, I am Denys van Kempen.
I am connected here to the SAP HANA cockpit, connected to a tenant database, HA0, and we
are looking at System Overview.
In the Monitoring section here we find a number of links and one of them is Monitor system
health.
Select it and the System Health app will open.
HA0 is a single node system, meaning that the SAP HANA database is running on a single
server, not on multiple hosts, also known as a distributed system, which would look
like this, where we have a column for each of the nodes of this system with in the header
the role, SAP HANA Worker and SAP HANA Standby.
Let’s return to our single-node system.
System Health provides a single view of the system and on the host through the use of
a couple of graphs.
First we see, as mentioned, the roles of the system in the header.
XS_WORKER_ROLE means that XS Advanced is installed on this system and the host also acts as an
XS Advanced application server.
We see the name, the status, and any critical alerts.
Selecting the Alerts would open the Alerts app, just as you would expect, the same response
as you would get from System Overview.
Then we have a number of graphs.
CPU (%), Memory (%), and Disk Usage (%) we also find on System Overview —hover over
to get some numbers— and we also have a graph here for the Network I/O (input/output),
Disk I/O, Statements and MVCC Versions, multi-versioning concurrency control.
If you select a graph, a pop-up opens with a more detailed view and some additional links
for further analysis.
For the CPU graph, for example, we can view the CPU chart, and this will open the Performance
Monitor with the CPU counters for all processes selected.
All metrics for this host, also opens Performance Monitor, now with all metrics, with all counters
displayed in the graph.
View CPU for all hosts, opens Performance Monitor with the CPU counters not only for
the host in question but for all hosts.
In a single host system, this is the same view as the first one.
For the Memory Graph, view memory chart, of course, will show us the memory metrics in
Performance Monitor.
View all metrics for this host is exactly the same as for CPU (all metrics), and the
same applies to memory for all hosts.
Analyze memory history opens another page, or app, I should say, Memory Analysis, which
provides a different view on the data.
You might be already familiar with this app but, if not, Memory Analysis is the topic
of another video tutorial.
Let’s return.
Out of Memory Events, as well, opens Memory Analysis, but now with the Out of Memory Events
tab displayed so you have instant access to this information.
You do not have to search for it.
Unloads, again, comes with a menu: View unloads chart plus a link to all metrics, which, you
have guessed it, will be the same as for CPU and Memory, and, should this have been a multiple
host system: view unloads for all hosts.
Usually, unloads are a normal occurrence.
Data stored in memory, currently not used, is freed up to load some other data.
If you start to get a high number of unloads, this may point to an issue which might require
further investigation.
8 corresponds to a very low number.
Alert 55 Column store unloads also monitors this metric for you.
Disk Usage (%) and Network I/O, as well, return the related metrics in Performance Monitor.
For Statements, we get an additional item, just like for Memory (%).
This time this is Analyze Workload, which opens Workload Analysis, and here we can view
Top SQL Statements, Background jobs, the Timeline with threads, and another one with focus on
all threads.
Workload Analysis is also the topic of a dedicated tutorial.
MVCC versions, does again what you would expect, same as for Statements, this time showing
active versions, acquired record locks and the active commit ID range.
Not everyone will be familiar with these metrics, of course.
The cockpit links to the documentation.
Here we find them all listed with a description.
This could be a little bit elaborated, in my view.
That the Acquired record locks KPI refers to the number of acquired record locks is
not very informative.
To get more information, you would have to enter the KPI in SAP’s Knowledge Base Search
on the SAP Support Portal and you will need an account for this.
In this case, for example, the FAQ on Lock Analysis for SAP HANA will answer most questions.
Disk I/O, finally, is very similar to the Network I/O chart, and to most of the others,
for that matter, and opens Performance Monitor for the Disk I/O counters: data write size,
log write size, backup write size, and data and log read size.
Not a lot of I/O going on.
It is an in-memory database after all.
OK —That’s it.
System Health Monitor.
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