This commit introduces the necessary logic to avoid that conflict. If a PLS component can identify that a daemon has failed, then we will set a flag indicating that fact. The xcast system will subsequently check that flag and, if it is set, will send all messages direct to the recipient. In the case of "kill local procs" and "terminate", the messages will go directly to each orted, thus bypassing any orted that has failed.
In addition, the xcast system will -not- wait for the messages to complete, but will return immediately (i.e., operate in non-blocking mode). Orterun will wait (via an event timer) for a period of time based on the number of daemons in the system to allow the messages to attempt to be delivered - at the end of that time, orterun will simply exit, alerting the user to the problem and -strongly- recommending they run orte-clean.
I could only test this on slurm for the case where all daemons unexpectedly died - srun apparently only executes its waitpid callback when all launched functions terminate. I have asked that Jeff integrate this capability into the OOB as he is working on it so that we execute it whenever a socket to an orted is unexpectedly closed. Meantime, the functionality will rarely get called, but at least the logic is available for anyone whose environment can support it.
This commit was SVN r16451.
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.
* 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
Cleanup ALL instances of output involving the printing of orte_process_name_t structures using the ORTE_NAME_ARGS macro so that the number of fields and type of data match. Replace those values with a new macro/function pair ORTE_NAME_PRINT that outputs a string (using the new thread safe data capability) so that any future changes to the printing of those structures can be accomplished with a change to a single point.
Note that I could not possibly find outputs that directly print the orte_process_name_t fields, but only dealt with those that used ORTE_NAME_ARGS. Hence, you may still have a few outputs that bark during compilation. Also, I could only verify those that fall within environments I can compile on, so other environments may yield some minor warnings.
This commit was SVN r15517.
Short description: major changes include -
1. singletons now fork/exec a local daemon to manage their operations.
2. the orte daemon code now resides in libopen-rte
3. daemons no longer use the orte triggering system during startup. Instead, they directly call back to their parent pls component to report ready to operate. A base function to count the callbacks has been provided.
I have modified all the pls components except xcpu and poe (don't understand either well enough to do it). Full functionality has been verified for rsh, SLURM, and TM systems. Compile has been verified for xgrid and gridengine.
This commit was SVN r15390.
* Remove the 'opal_mca_base_param_use_amca_sets' global variable
* Harness the fact that you can (read should) call the cmd_line functions
before initializing opal_init_util(). This pushes the MCA/GMCA/AMCA
command line options into the environment before OPAL inits and starts
to use these values. By putting the cmd_line parse before opal_init_util
in orterun and orted we only parse the *MCA parameter files once, and
correctly (alleviating the need to 'recache' the files on init.)
* Small bits of cleanup.
This commit was SVN r15219.
1. generalize orte_rml.xcast to become a general broadcast-like messaging system. Messages can now be sent to any tag on the daemons or processes. Note that any message sent via xcast will be delivered to ALL processes in the specified job - you don't get to pick and choose. At a later date, we will introduce an augmented capability that will use the daemons as relays, but will allow you to send to a specified array of process names.
2. extended orte_rml.xcast so it supports more scalable message routing methodologies. At the moment, we support three: (a) direct, which sends the message directly to all recipients; (b) linear, which sends the message to the local daemon on each node, which then relays it to its own local procs; and (b) binomial, which sends the message via a binomial algo across all the daemons, each of which then relays to its own local procs. The crossover points between the algos are adjustable via MCA param, or you can simply demand that a specific algo be used.
3. orteds no longer exhibit two types of behavior: bootproxy or VM. Orteds now always behave like they are part of a virtual machine - they simply launch a job if mpirun tells them to do so. This is another step towards creating an "orteboot" functionality, but also provided a clean system for supporting message relaying.
Note one major impact of this commit: multiple daemons on a node cannot be supported any longer! Only a single daemon/node is now allowed.
This commit is known to break support for the following environments: POE, Xgrid, Xcpu, Windows. It has been tested on rsh, SLURM, and Bproc. Modifications for TM support have been made but could not be verified due to machine problems at LANL. Modifications for SGE have been made but could not be verified. The developers for the non-verified environments will be separately notified along with suggestions on how to fix the problems.
This commit was SVN r15007.
via the visibility feature that is provided by some compilers.
Per default this feature is disabled, to enable it you need to
configure with --enable-visibility and obviously you need a compiler
with visibility support. Please refer to the wiki for more information.
https://svn.open-mpi.org/trac/ompi/wiki/Visibility
This commit was SVN r14582.
This completes the minor changes required to the PLS components. Basically, there is a small change required to the parameter list of the orted cmd functions. I caught and did it for xcpu and poe, in addition to the components listed in my email - so I think that only leaves xgrid unconverted.
The orted fail-to-start mods will also make changes in the PLS components, but those can be localized so they come in one at a time.
This commit was SVN r14499.
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.
Collect the base 'orted' command line into a base function since most of the
PLS components were duplicating this code. Add AMCA parameter command line
component to the base set.
Add Aggregate MCA parameter support to the following PLS components:
- gridengine
- process
- slurm
- poe
- tm
Improve support for 'rsh' component.
Did/could not support the following components:
- bproc
- proxy
- xcpu
- cnos
- xgrid
The above components had peculiar needs that made it non-trivial to add an
option. The authors of these components need to help in supporting this
new option.
I was only able to test the SLURM and RSH components due to system availability.
The others should work without problem.
This commit was SVN r14284.
The following Trac tickets were found above:
Ticket 976 --> https://svn.open-mpi.org/trac/ompi/ticket/976
Tested this functionality quite a bit more and made some fixes:
* Print far fewer help messages
* Fix one additional deadlock upon error
* Change some ORTE_LOG messages to silent (because they're not
errors)
* Some code got re-indented, sorry...
Discussed and reviewed with Ralph.
This commit was SVN r13375.
The following Trac tickets were found above:
Ticket 726 --> https://svn.open-mpi.org/trac/ompi/ticket/726
1. add a "cancel_operation" API to the pls components that allows orterun to demand that an orted operation (e.g., terminate_job) be immediately cancelled and abandoned.
2. changes the pls orted commands from blocking to non-blocking. This allows us to interrupt those operations should an orted be non-responsive. The change also adds an orte_abort_timeout that limits how long orterun will automatically wait for the orteds to respond - if the terminate command, for example, doesn't see orted response within that time, then we printout an appropriate error message and just give up.
3. modifies orterun to allow multiple ctrl-c's to simply abort the program even if the orteds have not responded
4. does some cleanup on the orte-level mca params so that their implementation looks a lot more like that of ompi - makes it easier to maintain. This change also includes the definition of an orte_abort_timeout struct and associated MCA param (can't have too many!) so you can set the time after which orterun gives up on waiting for orteds to respond
This needs more testing before migrating to 1.2.
This commit was SVN r13304.
Modify the RMAPS framework so we eliminate communicating a map to a backend node when certain attributes are set. The proxy functions are now implemented in the base, and a check made for HNP/non-HNP operation made in the map_jobs function prior to execution.
This commit was SVN r12619.
Note that Bproc won't support this operation, so we just ignore the --reuse-daemons directive.
I'm afraid I don't understand the POE and XGrid environments well enough to attempt the necessary modifications.
Also, please note that XGrid support has been broken on the trunk. I don't understand the code syntax well enough to make the required changes to that PLS component, so it won't compile at the moment. I'm hoping Brian has a few minutes to fix it after SC.
This commit was SVN r12614.
1. new functionality in the pls base to check for reusable daemons and launch upon them
2. an extension of the odls API to allow each odls component to build a notify message with the "correct" data in it for adding processes to the local daemon. This means that the odls now opens components on the HNP as well as on daemons - but that's the price of allowing so much flexibility. Only the default odls has this functionality enabled - the others just return NOT_IMPLEMENTED
3. addition of a new command line option "--reuse-daemons" to orterun. The default, for now, is to NOT reuse daemons. Once we have more time to test this capability, we may choose to reverse the default. For one thing, we probably want to investigate the tradeoffs in start time for comm_spawn'd processes that reuse daemons versus launch their own. On some systems, though, having another daemon show up can cause problems - so they may want to set the default as "reuse".
This is ONLY enabled for rsh launch, at the moment. The code needing to be added to each launcher is about three lines long, so I'll be doing that as I get access to machines I can test it on.
This commit was SVN r12608.
1. use non-blocking sends to transmit commands (this was actually done in a prior commit)
2. have an "ack" message sent back from the orted when it completes the command
The latter item is the new one here. With my prior commit, it was possible for the HNP to move on to other things before the orted had completed its command. This caused the HNP to occassionally exit before the orted, thus generating "lost connection" errors. With this change, we retain the parallel nature of the command communications, but still hold the HNP at that point until the orteds are done.
Best of both worlds.
This commit was SVN r12605.
Accordingly, there are new APIs to the name service to support the ability to get a job's parent, root, immediate children, and all its descendants. In addition, the terminate_job, terminate_orted, and signal_job APIs for the PLS have been modified to accept attributes that define the extent of their actions. For example, doing a "terminate_job" with an attribute of ORTE_NS_INCLUDE_DESCENDANTS will terminate the given jobid AND all jobs that descended from it.
I have tested this capability on a MacBook under rsh, Odin under SLURM, and LANL's Flash (bproc). It worked successfully on non-MPI jobs (both simple and including a spawn), and MPI jobs (again, both simple and with a spawn).
This commit was SVN r12597.
Add some debugger output to the ODLS default component.
Modify the orted command communication system so that it is done via non-blocking sends. This removes the linearity of the transmission and improves the response time.
This commit was SVN r12585.
Fix the persistent daemon problem where it was exiting when a job completed. Problem was that the persistent daemon would order the job daemons to exit. They would then send an 'ack' back to the persistent daemon - but the ack consisted of an echo of the "exit" command, which was recv'd by the wrong listener who treated it as a properly sent cmd....and exited.
This commit was SVN r12243.
This patch will cause a problem for cnos, however, as there we want to specifically tell the backends to be "null". I'm working on that issue.
This commit was SVN r12225.
I have tested on rsh, slurm, bproc, and tm. Bproc continues to have a problem (will be asking for help there).
Gridengine compiles but I cannot test (believe it likely will run).
Poe and xgrid compile to the extent they can without the proper include files.
This commit was SVN r12059.
