@@ -139,7 +139,7 @@ indicates the number of page faults which happened since the creation of

 the cgroup; this number can never decrease).

- - **cache:**

+ - **cache:**  

    the amount of memory used by the processes of this control group

    that can be associated precisely with a block on a block device.

    When you read from and write to files on disk, this amount will

@@ -149,16 +149,16 @@ the cgroup; this number can never decrease).

    `mmap`). It also accounts for the memory used by

    `tmpfs` mounts, though the reasons are unclear.

- - **rss:**

+ - **rss:**  

    the amount of memory that *doesn't* correspond to anything on disk:

    stacks, heaps, and anonymous memory maps.

- - **mapped_file:**

+ - **mapped_file:**  

    indicates the amount of memory mapped by the processes in the

    control group. It doesn't give you information about *how much*

    memory is used; it rather tells you *how* it is used.

- - **pgfault and pgmajfault:**

+ - **pgfault and pgmajfault:**  

    indicate the number of times that a process of the cgroup triggered

    a "page fault" and a "major fault", respectively. A page fault

    happens when a process accesses a part of its virtual memory space

@@ -177,10 +177,10 @@ the cgroup; this number can never decrease).

    it just has to duplicate an existing page, or allocate an empty

    page, it's a regular (or "minor") fault.

- - **swap:**

+ - **swap:**  

    the amount of swap currently used by the processes in this cgroup.

- - **active_anon and inactive_anon:**

+ - **active_anon and inactive_anon:**  

    the amount of *anonymous* memory that has been identified has

    respectively *active* and *inactive* by the kernel. "Anonymous"

    memory is the memory that is *not* linked to disk pages. In other

@@ -195,7 +195,7 @@ the cgroup; this number can never decrease).

    retagged "active". When the kernel is almost out of memory, and time

    comes to swap out to disk, the kernel will swap "inactive" pages.

- - **active_file and inactive_file:**

+ - **active_file and inactive_file:**  

    cache memory, with *active* and *inactive* similar to the *anon*

    memory above. The exact formula is cache = **active_file** +

    **inactive_file** + **tmpfs**. The exact rules used by the kernel

@@ -206,14 +206,14 @@ the cgroup; this number can never decrease).

    since it can be reclaimed immediately (while anonymous pages and

    dirty/modified pages have to be written to disk first).

- - **unevictable:**

+ - **unevictable:**  

    the amount of memory that cannot be reclaimed; generally, it will

    account for memory that has been "locked" with `mlock`.

    It is often used by crypto frameworks to make sure that

    secret keys and other sensitive material never gets swapped out to

    disk.

- - **memory and memsw limits:**

+ - **memory and memsw limits:**  

    These are not really metrics, but a reminder of the limits applied

    to this cgroup. The first one indicates the maximum amount of

    physical memory that can be used by the processes of this control

@@ -261,21 +261,21 @@ file in the kernel documentation, here is a short list of the most

 relevant ones:

- - **blkio.sectors:**

+ - **blkio.sectors:**  

    contain the number of 512-bytes sectors read and written by the

    processes member of the cgroup, device by device. Reads and writes

    are merged in a single counter.

- - **blkio.io_service_bytes:**

+ - **blkio.io_service_bytes:**  

    indicates the number of bytes read and written by the cgroup. It has

    4 counters per device, because for each device, it differentiates

    between synchronous vs. asynchronous I/O, and reads vs. writes.

- - **blkio.io_serviced:**

+ - **blkio.io_serviced:**  

    the number of I/O operations performed, regardless of their size. It

    also has 4 counters per device.

- - **blkio.io_queued:**

+ - **blkio.io_queued:**  

    indicates the number of I/O operations currently queued for this

    cgroup. In other words, if the cgroup isn't doing any I/O, this will

    be zero. Note that the opposite is not true. In other words, if

@@ -1,8 +1,5 @@

 <!--[metadata]>

 +++

-aliases = [

-"/engine/swarm/how-swarm-mode-works/"

-]

 title = "How services work"

 description = "How swarm mode services work"

 keywords = ["docker, container, cluster, swarm mode, node"]