[SERVER-6528] mongod pmap contain db files not in one copy Created: 19/Jul/12 Updated: 15/Aug/12 Resolved: 20/Jul/12 |
|
| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Question | Priority: | Major - P3 |
| Reporter: | Azat Khuzhin | Assignee: | Unassigned |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Attachments: |
|
| Participants: |
| Comments |
| Comment by Azat Khuzhin [ 20/Jul/12 ] |
|
Thanks for the explanation |
| Comment by Andy Schwerin [ 20/Jul/12 ] |
|
It does not increase the physical memory consumption. The private view and shared view are nearly the same, except that the private view contains writes that have not yet been retired out of the journal. Up to 100MB worth of data in the two views are allowed to be distinct, but this could be thought of as space to buffer uncommitted writes. The virtual address space consumption is a little under double the physical memory consumption, for this reason. On 64-bit x86 systems available today, this would limit a single mongod to storing around 64TB worth of data, even though there are 128TB of virtual address space available to a process. |
| Comment by Azat Khuzhin [ 20/Jul/12 ] |
|
Does this increase the memory usage? |
| Comment by Eliot Horowitz (Inactive) [ 20/Jul/12 ] |
|
This is normal. |
| Comment by Azat Khuzhin [ 19/Jul/12 ] |
|
Is it normal and why it is possible? |