404 past a certain zoom level and other memory questions

General talk
1

Hello all,

I am new to OSM and building tile servers, but I’m happy to be part of the community!

I recently built a tile server using the below guide provided by @SomeoneElse.
https://wiki.openstreetmap.org/wiki/User:SomeoneElse/Ubuntu_1604_tileserver_load

It works well (if not a bit slow).

However, whenever I go past a certain zoom level (it was 10 before, now it is 12), the tile server responds back with a 404.

For example:
http:///hot/11/1016/665.png
gives back the tile as it should.

but

http:///hot/12/4060/2671.png
gives me a 404, and kills renderd

renderd[26715]: DEBUG: Got command RenderPrio fd(28) xml(ajt), z(13), x(4061), y(2671), mime(image/png), options()
renderd[26715]: DEBUG: Got incoming request with protocol version 2
renderd[26715]: DEBUG: Got command RenderPrio fd(27) xml(ajt), z(13), x(4064), y(2672), mime(image/png), options()
renderd[26715]: DEBUG: Got incoming connection, fd 29, number 18
renderd[26715]: DEBUG: Got incoming request with protocol version 2
renderd[26715]: DEBUG: Got command RenderPrio fd(29) xml(ajt), z(13), x(4062), y(2672), mime(image/png), options()
renderd[26715]: DEBUG: Got incoming connection, fd 30, number 19
renderd[26715]: DEBUG: Got incoming request with protocol version 2
renderd[26715]: DEBUG: Got command RenderPrio fd(30) xml(ajt), z(13), x(4061), y(2672), mime(image/png), options()
renderd[26715]: DEBUG: Got incoming connection, fd 31, number 20
renderd[26715]: DEBUG: Got incoming request with protocol version 2
renderd[26715]: DEBUG: Got command RenderPrio fd(31) xml(ajt), z(13), x(4063), y(2672), mime(image/png), options()
renderd[26715]: DEBUG: Got incoming connection, fd 32, number 21
renderd[26715]: DEBUG: Got incoming request with protocol version 2
renderd[26715]: DEBUG: Got command RenderPrio fd(32) xml(ajt), z(13), x(4060), y(2671), mime(image/png), options()
Killed

I’m wondering if this may be a memory thing
Here is what I get when I run “free mem”


              total        used        free      shared  buff/cache   available
Mem:        1014516      254108      509312      165544      251096      469748
Swap:             0           0           0

How do I know what is enough memory?
How do I stop renderd from crashing?
Is there a better way to debug this?
Is there a way to cache every tile for quick loading or is that too much of a strain?
If you cache everything, how do you change it when you update the map?

Thank you all!

2

If renderd is getting killed because it’s out of memory, try:

o allocating more memory if you can (easy for a VM, not so easy if not)

o using fewer parallel rendering threads. Reduce “num_threads=4” in renderd.conf to a smaller number.

3

Is there a way to better debug why it is crashing?

4

Beyond “because it’s running out of memory” it’s difficult to say. I’ve never looked into how (for example) changing style would change the memory footprint.

5

Try running renderd in foreground by using “-f” or “–foreground”

regards
walter

6

Hey Walter. Thanks for the help. The above message where it says it was killed is when I was running it in the foreground. However, the debug messages are not helpful. Is there a way I can get the error messages that are killing it?

7

check /var/log/syslog. may be there is something like “OOM Killer”
see https://unix.stackexchange.com/questions/153585/how-does-the-oom-killer-decide-which-process-to-kill-first#153586

using linux another way is using strace. eg strace -o renderd.trace -f -s 1024 renderd -f …

walter