After much work by Jeff and myself, and quite a lot of discussion, it has become clear that we simply cannot resolve the infinite loops caused by RML-involved subsystems calling orte_output. The original rationale for the change to orte_output has also been reduced by shifting the output of XML-formatted vs human readable messages to an alternative approach.
I have globally replaced the orte_output/ORTE_OUTPUT calls in the code base, as well as the corresponding .h file name. I have test compiled and run this on the various environments within my reach, so hopefully this will prove minimally disruptive.
This commit was SVN r18619.
such, the commit message back to the master SVN repository is fairly
long.
= ORTE Job-Level Output Messages =
Add two new interfaces that should be used for all new code throughout
the ORTE and OMPI layers (we already make the search-and-replace on
the existing ORTE / OMPI layers):
* orte_output(): (and corresponding friends ORTE_OUTPUT,
orte_output_verbose, etc.) This function sends the output directly
to the HNP for processing as part of a job-specific output
channel. It supports all the same outputs as opal_output()
(syslog, file, stdout, stderr), but for stdout/stderr, the output
is sent to the HNP for processing and output. More on this below.
* orte_show_help(): This function is a drop-in-replacement for
opal_show_help(), with two differences in functionality:
1. the rendered text help message output is sent to the HNP for
display (rather than outputting directly into the process' stderr
stream)
1. the HNP detects duplicate help messages and does not display them
(so that you don't see the same error message N times, once from
each of your N MPI processes); instead, it counts "new" instances
of the help message and displays a message every ~5 seconds when
there are new ones ("I got X new copies of the help message...")
opal_show_help and opal_output still exist, but they only output in
the current process. The intent for the new orte_* functions is that
they can apply job-level intelligence to the output. As such, we
recommend that all new ORTE and OMPI code use the new orte_*
functions, not thei opal_* functions.
=== New code ===
For ORTE and OMPI programmers, here's what you need to do differently
in new code:
* Do not include opal/util/show_help.h or opal/util/output.h.
Instead, include orte/util/output.h (this one header file has
declarations for both the orte_output() series of functions and
orte_show_help()).
* Effectively s/opal_output/orte_output/gi throughout your code.
Note that orte_output_open() takes a slightly different argument
list (as a way to pass data to the filtering stream -- see below),
so you if explicitly call opal_output_open(), you'll need to
slightly adapt to the new signature of orte_output_open().
* Literally s/opal_show_help/orte_show_help/. The function signature
is identical.
=== Notes ===
* orte_output'ing to stream 0 will do similar to what
opal_output'ing did, so leaving a hard-coded "0" as the first
argument is safe.
* For systems that do not use ORTE's RML or the HNP, the effect of
orte_output_* and orte_show_help will be identical to their opal
counterparts (the additional information passed to
orte_output_open() will be lost!). Indeed, the orte_* functions
simply become trivial wrappers to their opal_* counterparts. Note
that we have not tested this; the code is simple but it is quite
possible that we mucked something up.
= Filter Framework =
Messages sent view the new orte_* functions described above and
messages output via the IOF on the HNP will now optionally be passed
through a new "filter" framework before being output to
stdout/stderr. The "filter" OPAL MCA framework is intended to allow
preprocessing to messages before they are sent to their final
destinations. The first component that was written in the filter
framework was to create an XML stream, segregating all the messages
into different XML tags, etc. This will allow 3rd party tools to read
the stdout/stderr from the HNP and be able to know exactly what each
text message is (e.g., a help message, another OMPI infrastructure
message, stdout from the user process, stderr from the user process,
etc.).
Filtering is not active by default. Filter components must be
specifically requested, such as:
{{{
$ mpirun --mca filter xml ...
}}}
There can only be one filter component active.
= New MCA Parameters =
The new functionality described above introduces two new MCA
parameters:
* '''orte_base_help_aggregate''': Defaults to 1 (true), meaning that
help messages will be aggregated, as described above. If set to 0,
all help messages will be displayed, even if they are duplicates
(i.e., the original behavior).
* '''orte_base_show_output_recursions''': An MCA parameter to help
debug one of the known issues, described below. It is likely that
this MCA parameter will disappear before v1.3 final.
= Known Issues =
* The XML filter component is not complete. The current output from
this component is preliminary and not real XML. A bit more work
needs to be done to configure.m4 search for an appropriate XML
library/link it in/use it at run time.
* There are possible recursion loops in the orte_output() and
orte_show_help() functions -- e.g., if RML send calls orte_output()
or orte_show_help(). We have some ideas how to fix these, but
figured that it was ok to commit before feature freeze with known
issues. The code currently contains sub-optimal workarounds so
that this will not be a problem, but it would be good to actually
solve the problem rather than have hackish workarounds before v1.3 final.
This commit was SVN r18434.
This commit brings over all the work from the /tmp-public/datarep
branch. See commits r16855, r16859, r16860 for the highlights of what
was done.
This commit was SVN r16891.
The following SVN revisions from the original message are invalid or
inconsistent and therefore were not cross-referenced:
r16855
r16859
r16860
The following Trac tickets were found above:
Ticket 1029 --> https://svn.open-mpi.org/trac/ompi/ticket/1029
The commit has been tested for C/R and Cray operations, and on Odin (SLURM, rsh) and RoadRunner (TM). I tried to update all environments, but obviously could not test them. I know that Windows needs some work, and have highlighted what is know to be needed in the odls process component.
This represents a lot of work by Brian, Tim P, Josh, and myself, with much advice from Jeff and others. For posterity, I have appended a copy of the email describing the work that was done:
As we have repeatedly noted, the modex operation in MPI_Init is the single greatest consumer of time during startup. To-date, we have executed that operation as an ORTE stage gate that held the process until a startup message containing all required modex (and OOB contact info - see #3 below) info could be sent to it. Each process would send its data to the HNP's registry, which assembled and sent the message when all processes had reported in.
In addition, ORTE had taken responsibility for monitoring process status as it progressed through a series of "stage gates". The process reported its status at each gate, and ORTE would then send a "release" message once all procs had reported in.
The incoming changes revamp these procedures in three ways:
1. eliminating the ORTE stage gate system and cleanly delineating responsibility between the OMPI and ORTE layers for MPI init/finalize. The modex stage gate (STG1) has been replaced by a collective operation in the modex itself that performs an allgather on the required modex info. The allgather is implemented using the orte_grpcomm framework since the BTL's are not active at that point. At the moment, the grpcomm framework only has a "basic" component analogous to OMPI's "basic" coll framework - I would recommend that the MPI team create additional, more advanced components to improve performance of this step.
The other stage gates have been replaced by orte_grpcomm barrier functions. We tried to use MPI barriers instead (since the BTL's are active at that point), but - as we discussed on the telecon - these are not currently true barriers so the job would hang when we fell through while messages were still in process. Note that the grpcomm barrier doesn't actually resolve that problem, but Brian has pointed out that we are unlikely to ever see it violated. Again, you might want to spend a little time on an advanced barrier algorithm as the one in "basic" is very simplistic.
Summarizing this change: ORTE no longer tracks process state nor has direct responsibility for synchronizing jobs. This is now done via collective operations within the MPI layer, albeit using ORTE collective communication services. I -strongly- urge the MPI team to implement advanced collective algorithms to improve the performance of this critical procedure.
2. reducing the volume of data exchanged during modex. Data in the modex consisted of the process name, the name of the node where that process is located (expressed as a string), plus a string representation of all contact info. The nodename was required in order for the modex to determine if the process was local or not - in addition, some people like to have it to print pretty error messages when a connection failed.
The size of this data has been reduced in three ways:
(a) reducing the size of the process name itself. The process name consisted of two 32-bit fields for the jobid and vpid. This is far larger than any current system, or system likely to exist in the near future, can support. Accordingly, the default size of these fields has been reduced to 16-bits, which means you can have 32k procs in each of 32k jobs. Since the daemons must have a vpid, and we require one daemon/node, this also restricts the default configuration to 32k nodes.
To support any future "mega-clusters", a configuration option --enable-jumbo-apps has been added. This option increases the jobid and vpid field sizes to 32-bits. Someday, if necessary, someone can add yet another option to increase them to 64-bits, I suppose.
(b) replacing the string nodename with an integer nodeid. Since we have one daemon/node, the nodeid corresponds to the local daemon's vpid. This replaces an often lengthy string with only 2 (or at most 4) bytes, a substantial reduction.
(c) when the mca param requesting that nodenames be sent to support pretty error messages, a second mca param is now used to request FQDN - otherwise, the domain name is stripped (by default) from the message to save space. If someone wants to combine those into a single param somehow (perhaps with an argument?), they are welcome to do so - I didn't want to alter what people are already using.
While these may seem like small savings, they actually amount to a significant impact when aggregated across the entire modex operation. Since every proc must receive the modex data regardless of the collective used to send it, just reducing the size of the process name removes nearly 400MBytes of communication from a 32k proc job (admittedly, much of this comm may occur in parallel). So it does add up pretty quickly.
3. routing RML messages to reduce connections. The default messaging system remains point-to-point - i.e., each proc opens a socket to every proc it communicates with and sends its messages directly. A new option uses the orteds as routers - i.e., each proc only opens a single socket to its local orted. All messages are sent from the proc to the orted, which forwards the message to the orted on the node where the intended recipient proc is located - that orted then forwards the message to its local proc (the recipient). This greatly reduces the connection storm we have encountered during startup.
It also has the benefit of removing the sharing of every proc's OOB contact with every other proc. The orted routing tables are populated during launch since every orted gets a map of where every proc is being placed. Each proc, therefore, only needs to know the contact info for its local daemon, which is passed in via the environment when the proc is fork/exec'd by the daemon. This alone removes ~50 bytes/process of communication that was in the current STG1 startup message - so for our 32k proc job, this saves us roughly 32k*50 = 1.6MBytes sent to 32k procs = 51GBytes of messaging.
Note that you can use the new routing method by specifying -mca routed tree - if you so desire. This mode will become the default at some point in the future.
There are a few minor additional changes in the commit that I'll just note in passing:
* propagation of command line mca params to the orteds - fixes ticket #1073. See note there for details.
* requiring of "finalize" prior to "exit" for MPI procs - fixes ticket #1144. See note there for details.
* cleanup of some stale header files
This commit was SVN r16364.
mpi_show_mpi_alloc_mem_leaks
When activated, MPI_FINALIZE displays a list of memory allocations
from MPI_ALLOC_MEM that were not freed by MPI_FREE_MEM (in each MPI
process).
* If set to a positive integer, display only that many leaks.
* If set to a negative integer, display all leaks.
* If set to 0, do not show any leaks.
This commit was SVN r15736.
* General TCP cleanup for OPAL / ORTE
* Simplifying the OOB by moving much of the logic into the RML
* Allowing the OOB RML component to do routing of messages
* Adding a component framework for handling routing tables
* Moving the xcast functionality from the OOB base to its own framework
Includes merge from tmp/bwb-oob-rml-merge revisions:
r15506, r15507, r15508, r15510, r15511, r15512, r15513
This commit was SVN r15528.
The following SVN revisions from the original message are invalid or
inconsistent and therefore were not cross-referenced:
r15506
r15507
r15508
r15510
r15511
r15512
r15513
than just the PML/BTLs these days. Also clean up the code so that it
handles the situation where not all nodes register information for a given
node (rather than just spinning until that node sends information, like
we do today).
Includes r15234 and r15265 from the /tmp/bwb-modex branch.
This commit was SVN r15310.
The following SVN revisions from the original message are invalid or
inconsistent and therefore were not cross-referenced:
r15234
r15265
The primary change that underlies all this is in the OOB. Specifically, the problem in the code until now has been that the OOB attempts to resolve an address when we call the "send" to an unknown recipient. The OOB would then wait forever if that recipient never actually started (and hence, never reported back its OOB contact info). In the case of an orted that failed to start, we would correctly detect that the orted hadn't started, but then we would attempt to order all orteds (including the one that failed to start) to die. This would cause the OOB to "hang" the system.
Unfortunately, revising how the OOB resolves addresses introduced a number of additional problems. Specifically, and most troublesome, was the fact that comm_spawn involved the immediate transmission of the rendezvous point from parent-to-child after the child was spawned. The current code used the OOB address resolution as a "barrier" - basically, the parent would attempt to send the info to the child, and then "hold" there until the child's contact info had arrived (meaning the child had started) and the send could be completed.
Note that this also caused comm_spawn to "hang" the entire system if the child never started... The app-failed-to-start helped improve that behavior - this code provides additional relief.
With this change, the OOB will return an ADDRESSEE_UNKNOWN error if you attempt to send to a recipient whose contact info isn't already in the OOB's hash tables. To resolve comm_spawn issues, we also now force the cross-sharing of connection info between parent and child jobs during spawn.
Finally, to aid in setting triggers to the right values, we introduce the "arith" API for the GPR. This function allows you to atomically change the value in a registry location (either divide, multiply, add, or subtract) by the provided operand. It is equivalent to first fetching the value using a "get", then modifying it, and then putting the result back into the registry via a "put".
This commit was SVN r14711.
There is a binomial algorithm in the code (i.e., the HNP would send to a subset of the orteds, which then relay it on according to the typical log-2 algo), but that has a bug in it so the code won't let you select it even if you tried (and the mca param doesn't show, so you'd *really* have to try).
This also involved a slight change to the oob.xcast API, so propagated that as required.
Note: this has *only* been tested on rsh, SLURM, and Bproc environments (now that it has been transferred to the OMPI trunk, I'll need to re-test it [only done rsh so far]). It should work fine on any environment that uses the ORTE daemons - anywhere else, you are on your own... :-)
Also, correct a mistake where the orte_debug_flag was declared an int, but the mca param was set as a bool. Move the storage for that flag to the orte/runtime/params.c and orte/runtime/params.h files appropriately.
This commit was SVN r14475.
This merge adds Checkpoint/Restart support to Open MPI. The initial
frameworks and components support a LAM/MPI-like implementation.
This commit follows the risk assessment presented to the Open MPI core
development group on Feb. 22, 2007.
This commit closes trac:158
More details to follow.
This commit was SVN r14051.
The following SVN revisions from the original message are invalid or
inconsistent and therefore were not cross-referenced:
r13912
The following Trac tickets were found above:
Ticket 158 --> https://svn.open-mpi.org/trac/ompi/ticket/158
- we have to be able to attach a string to an error class, not just to an
error code
- according to MPI-2 the attribute MPI_LASTUSEDCODE has to be updated
everytime you add a new code or a new class. Thus, you have to have single
list for both.
Thus, we got rid of the error_class structure. In the error-code structure, we
can distinguish whether we are dealing with an error code or an error class by
looking at the err->code element of the structure. In case its value is
MPI_UNDEFINED, the according entry is a class, else it is an error code. All
predefined error codes have the code and the class field set to the same
value.
The test MPI_Add_error_class1 passes now.
Fixes trac:418
This commit was SVN r12764.
The following Trac tickets were found above:
Ticket 418 --> https://svn.open-mpi.org/trac/ompi/ticket/418
the same time, remove some of the MPI-related options from OPAL:
- provide mechanism to change at runtime whether sched_yield() should
be called when the progress engine is idle
- provide mechanism for changing the rate at which the event engine
is called when there are "no" users of the event engine (ie, when
using MPI but not TCP)
- fix some function names in the progress engine to better match
their intended use (and remove MPI naming scheme)
- remove progress_mpi_enable / progress_mpi_disable because
we can now use the functions to set the sched_yield and
tick rate interfaces
- rename opal_progress_events() to opal_progress_set_event_flag()
because the first really isn't descriptive of what the function
does and I always got confused by it
This commit was SVN r12645.
Other changes:
1. Remove the old xcpu components as they are not functional.
2. Fix a "bug" in orterun whereby we called dump_aborted_procs even when we normally terminated. There is still some kind of bug in this procedure, however, as we appear to be calling the orterun job_state_callback function every time a process terminates (instead of only once when they have all terminated). I'll continue digging into that one.
This will require an autogen/configure, I'm afraid.
This commit was SVN r11228.
did pre-libevent update. The problem is that the behavior of
OPAL_EVLOOP_ONCE was changed by the OMPI team, which them broke things
during the update, so it had to be reverted to the old meaning of
loop until one event occurs. OPAL_EVLOOP_ONELOOP will go through the
event loop once (like EVLOOP_NONBLOCK) but will pause in the event
library for a bit (like EVLOOP_ONCE).
fixes trac:234
This commit was SVN r11081.
The following Trac tickets were found above:
Ticket 234 --> https://svn.open-mpi.org/trac/ompi/ticket/234
- My original patch stands: MPI_FINALIZE directly invokes the
attribute callbacks on MPI_COMM_SELF
- We added some user-level checks to ensure that they don't call
MPI_FINALIZE twice (this isn't really required, but it will prevent
whacky segv's -- they'll at least get a nice error message)
- Removed the attribute callbacks on MPI_COMM_SELF from
ompi_mpi_comm_finalize (i.e., we just moved them from
ompi_mpi_comm_finalize to ompi_mpi_finalize -- we just moved this
process up earlier in the MPI_FINALIZE sequence of events)
- Because there were so many conversations about this, here's the
rationale:
- MPI-2:4.8 says that we have to MPI_COMM_FREE MPI_COMM_SELF so that
the attribute callbacks are invoked.
- After considerable discussion, we came to the conclusion that
FREE'ing COMM_SELF is not the issue -- calling the callbacks is
the issue.
- So it is sufficent for MPI_FINALIZE to directly invoke these
attribute callbacks
- The attribute callbacks are *not* invoked on other communicators
because said communicators are not MPI_COMM_FREE'ed
This commit was SVN r9628.
- move files out of toplevel include/ and etc/, moving it into the
sub-projects
- rather than including config headers with <project>/include,
have them as <project>
- require all headers to be included with a project prefix, with
the exception of the config headers ({opal,orte,ompi}_config.h
mpi.h, and mpif.h)
This commit was SVN r8985.
complete, but stable enough that it will have no impact on general development,
so into the trunk it goes. Changes in this commit include:
- Remove the --with option for disabling MPI-2 onesided support. It
complicated code, and has no real reason for existing
- add a framework osc (OneSided Communication) for encapsulating
all the MPI-2 onesided functionality
- Modify the MPI interface functions for the MPI-2 onesided chapter
to properly call the underlying framework and do the required
error checking
- Created an osc component pt2pt, which is layered over the BML/BTL
for communication (although it also uses the PML for long message
transfers). Currently, all support functions, all communication
functions (Put, Get, Accumulate), and the Fence synchronization
function are implemented. The PWSC active synchronization
functions and Lock/Unlock passive synchronization functions are
still not implemented
This commit was SVN r8836.
Here's the huge registry check-in you've all been waiting for with baited breath. The revised version sends a single message to all processes at the various stage gates, thus making the startup much more scalable. I could provide you with all the tawdry details, but won't for now - you are welcome to ask, though, and I'll merrily bore your ears to tears.
In addition, the commit contains the following:
1. set the ignore properties on ompi/debuggers and orte/mca/pls/poe
2. Added simplified subscribe and put functions to the registry's API. I have also converted all of the ompi functions that registered subscriptions to the new API, and caught their associated put's as well.
In a follow-on commit, I'll be adding support for George's hetero arch registry subscription (wanted to get this one in first).
This commit was SVN r7118.
tree.
- fix up #include's throughout the tree (yay contrib/search_replace.pl!)
- remove a few extraneous #include's
- remove orte_sys_info*() from opal_init()/opal_finalize() (it's
already in orte_init_stage1() and orte_system_finalize())
- remove dependencies in opal on orte_system_info -- util/os_path.c
and util/os_create_dirpath.c (they only used path_sep, anyway --
easily changed to #defines)
This commit was SVN r7059.
API is still a bit unstable and may change.
- Add a primitive "first use" component that simply has each process
"touch" the pages that they want to use, thereby [hopefully] locking
them locally to a specific processor
- Add hooks in ompi_mpi_init to enable memory affinity when processor
affinity is used.
- Added hooks in ompi_mpi_finalize to shut down memory affinity when
it was initialized during ompi_mpi_init.
- Added right hooks in ompi_info to display maffinity components.
This commit was SVN r7044.
Change all the places where they are used to fit the new name.
Remove the code to check the remote arch from the PML. We will have a GPR mechanism
in ompi_mpi_initialize to do that.
This commit was SVN r6750.
This required a little fiddling with a number of areas. Biggest problem was that it uncovered a potential for an infinite loop to be created in the registry. If a callback function modified the registry, the registry checked the triggers to see if anything had fired. Well, if the original callback was due to a trigger firing, that condition hadn't changed - so the trigger fired again....which caused the callback to be called, which modified the registry, which checked the triggers, etc. etc.
Triggers are now checked and then "flagged" as being "in process" so that the registry will NOT recheck that trigger until all callbacks have been processed. Tried doing this with subscriptions as well, but that caused a problem - when we release processes from a stagegate, they (at the moment) immediately place data on the registry that should cause a subscription to fire. Unfortunately, the system will just hang if that subscription doesn't get processed. So, I have left the subscription system alone - any callback function that modifies the registry in a fashion that will fire a subscription will indeed fire that subscription. We'll have to see if this causes problems - it shouldn't, but a careless user could lock things up if the callback generates a callback to itself.
Also fixed the code that placed a process' RML contact info on the registry to eliminate the leading '/' from the string.
This commit was SVN r6684.