8.4.2. DVM Bootstrap Implementation Plan

This document describes the implementation that turns the partial bootstrap draft into a working launcher-less DVM. The externally observable contract it delivers — the configuration-file semantics, identity derivation, controller self-election, and wireup — is specified in DVM Bootstrap: Specification, which is authoritative for observable behavior. Where this plan and that specification disagree, the specification wins and this plan must be corrected.

8.4.2.1. Approach

The guiding principle is reuse the existing daemon-startup plumbing instead of building a parallel one. A normally-launched prted receives its identity, its DVM size, and its HNP’s contact URI from environment variables (MCA parameters) that its launcher sets before exec; the ess and rml layers then read those parameters during prte_init. Bootstrap has no launcher, but it runs prte_ess_base_bootstrap() before prte_init and can set exactly the same environment. So the bootstrap code’s job is narrow and well-defined:

1. Parse prte.conf (shared parser, Step 1).

2. Compute this node’s identity and role from the parsed values (Step 2).

3. Express that identity through the same MCA parameters a launcher would have set (Steps 3–7).

4. Choose the process type passed to prte_init — HNP for the controller, ordinary daemon otherwise (Step 8).

Everything downstream — name assignment, routing-tree computation, RML contact setup, session directories — then happens through the unchanged existing code paths. The structural changes outside the bootstrap files are small and confined to Step 8: prted.c branches on the election result to initialize as the HNP when it is the controller, and the redundant --bootstrap handling is removed from prte (prte.c and schizo_prte.c).

The following table is the crux of the design: for each thing a launcher normally provides, it names the MCA parameter / environment variable bootstrap sets and where that value is consumed.

Value	Set by bootstrap as	Consumed by
Controller namespace + rank	PMIX_SERVER_NSPACE = <ClusterName>-prte-dvm, PMIX_SERVER_RANK = 0	prte_plm_base_set_hnp_name() (uses these directly, no @0 suffix) — controller only
Daemon namespace	PRTE_MCA_ess_base_nspace = <ClusterName>-prte-dvm	ess/env env_set_name() — non-controller daemons
Daemon rank (vpid)	PRTE_MCA_ess_base_vpid = computed rank	ess/env env_set_name()
DVM daemon count	PRTE_MCA_ess_base_num_procs = daemon count	ess/env (sets prte_process_info.num_daemons, which drives prte_rml_compute_routing_tree())
Controller contact URI	PRTE_MCA_prte_hnp_uri = synthesized URI (Step 4)	prte_process_info.my_hnp_uri → rml.c non-master branch
Listening port	PRTE_MCA_prte_static_ipv4_ports or PRTE_MCA_prte_static_ipv6_ports = DVMPort (family per DVMIPVersion; every process)	oob/tcp listener
Address family	PRTE_MCA_prte_disable_ipv6_family / ..._ipv4_family = 0/1 (per DVMIPVersion)	oob/tcp family selection
Inter-node networks	PRTE_MCA_prte_if_include = DVMNetworks	prte_if_include (interface/subnet selection in oob/tcp)
Interface netmask	written into the synthesized PRTE_MCA_prte_hnp_uri mask field (Step 4); not a standalone MCA parameter	set_addr() reachability filtering
FQDN matching	PRTE_MCA_prte_keep_fqdn_hostnames = 0/1	prte_keep_fqdn_hostnames (host matching in proc_info.c)

Because bootstrap runs before prte_init opens and registers any framework, setting these in the environment (with PMIx_Setenv) is sufficient: each framework’s register reads its value from the environment as usual.

8.4.2.1.1. Precedence: config file trumps the MCA param file

Several of the keys above (DVMNetworks, KeepFQDNHostnames, DVMPort) duplicate values an administrator could otherwise set as MCA parameters. They are included in prte.conf deliberately, so a site can manage all DVM behavior in one place. The required precedence is that a value set in ``prte.conf`` overrides the same value in an MCA parameter file.

This falls out naturally from setting the values as environment MCA parameters: PMIx MCA precedence already ranks an environment variable above a parameter file, and a command-line --prtemca above the environment. So bootstrap sets each config-derived value with PMIx_Setenv(..., overwrite = true): it beats the operator’s default MCA param file (as required) while still yielding to an explicit command-line override. The one exception is a value bootstrap supplies as its own fallback default rather than from the config file — notably the retry parameters of Step 7, which have no config key — where overwrite = false is used so any operator MCA setting still wins.

8.4.2.2. Step 1 — Factor the config parser into a shared utility

The Key=Value reader and the DVMNodes regular-expression expander are today duplicated verbatim between src/mca/ess/base/ess_base_bootstrap.c and src/mca/ras/bootstrap/ras_boot.c. The spec requires the two consumers to interpret a configuration file identically, so the parser must become a single implementation both call.

Create src/util/prte_bootstrap.c / src/util/prte_bootstrap.h holding:

/* All values parsed from prte.conf, owned by the struct. */
typedef struct {
    char     *cluster;          /* ClusterName (default "cluster") */
    char     *ctrlhost;         /* DVMControllerHost (required) */
    uint32_t  port;             /* DVMPort (default 7817) */
    int       ip_version;       /* DVMIPVersion: 4 (default) or 6 */
    int       radix;            /* DVMRadix (default 64) */
    uint32_t  connect_max_time; /* DVMConnectMaxTime seconds (default 30) */
    char    **nodes;            /* expanded DVMNodes (required) */
    bool      keep_fqdn;        /* KeepFQDNHostnames (default false) */
    char     *dvm_networks;     /* DVMNetworks (default NULL -> all) */
    char     *dvm_netmask;      /* DVMNetmask (default NULL -> empty) */
    uint32_t  retry_max_delay;  /* DVMRetryMaxDelay seconds (default 5) */
    char     *dvmtmpdir;
    char     *sessiontmpdir;
    char     *ctrllogpath;
    char     *prtedlogpath;
    bool      ctrl_log_jobstate, ctrl_log_procstate;
    bool      prted_log_jobstate, prted_log_procstate;
} prte_bootstrap_config_t;

/* Read <sysconfdir>/prte.conf, validate required keys, expand DVMNodes.
 * Emits the help-prte-runtime.txt bootstrap diagnostics on error. */
int prte_bootstrap_parse(prte_bootstrap_config_t *cfg);
void prte_bootstrap_config_free(prte_bootstrap_config_t *cfg);

Move the file reader, regex_extract_nodes, regex_parse_value_ranges, regex_parse_value_range, and read_file (all currently duplicated) into this file as the single implementation. The keys the draft does not yet parse — KeepFQDNHostnames, DVMNetworks, DVMNetmask, DVMIPVersion, DVMRadix, DVMConnectMaxTime, DVMRetryMaxDelay, and the log-state booleans — are added to the parser here, and the split DVMControllerPort/PRTEDPort keys are collapsed to the single DVMPort. ess_base_bootstrap.c and ras_boot.c are reduced to callers of prte_bootstrap_parse().

Register the new object files in src/util/Makefile.am.

8.4.2.3. Step 2 — Compute identity and elect the controller

This is the new logic the draft lacks entirely. It lives in prte_ess_base_bootstrap() and runs after prte_bootstrap_parse().

Namespace. The DVM namespace is <cfg.cluster>-prte-dvm, identical on every node.

Controller election. Compare the local node to cfg.ctrlhost using the existing prte_check_host_is_local() helper (which already handles aliases and IP addresses); the cfg.keep_fqdn value is applied first so the comparison is short-form or fully-qualified per the configuration. The single node that matches is the controller.

Rank assignment follows the resolved rule from the spec:

rank_of(node):
    if node == ctrlhost:            return 0
    r = 1
    for entry in DVMNodes (listed order):
        if entry == ctrlhost:       continue     # controller is rank 0
        if entry == node:           return r
        r = r + 1
    return NOT_FOUND                              # not a member -> abort

Every daemon runs this against its own node. The daemon count is len(DVMNodes) when ctrlhost appears in DVMNodes (it is counted as a compute node) and len(DVMNodes) + 1 when it does not. A daemon that is neither the controller nor found in DVMNodes fails the bootstrap with a diagnostic (a new help-prte-runtime.txt entry, e.g. bootstrap-node-not-member) rather than guessing a rank.

The function computes (is_controller, my_rank, num_daemons) and passes them to Step 3.

8.4.2.4. Step 3 — Publish identity through the existing MCA plumbing

With identity computed, bootstrap sets the environment per the table in Approach, then returns to prted.c which selects the process type.

The steps here are grouped by concern, not by execution order: the family-dependent values used below — port_param (the name of the static-port MCA parameter) and port_str (DVMPort as a string) — are resolved in Step 5, which runs before this publishing so the correct family-specific parameter is set.

Controller path:

PMIx_Setenv("PMIX_SERVER_NSPACE", dvm_nspace, true, &environ);
PMIx_Setenv("PMIX_SERVER_RANK", "0", true, &environ);
/* listen on the shared well-known DVM port */
PMIx_Setenv(port_param, port_str, true, &environ);   /* family-specific; see Step 5 */
*is_controller = true;

prte_plm_base_set_hnp_name() already honors PMIX_SERVER_NSPACE / PMIX_SERVER_RANK and, on that path, uses the namespace verbatim (no @0 suffix), so the controller’s daemon namespace is exactly <ClusterName>-prte-dvm and its rank is 0 — the values every compute daemon assumes when it synthesizes the controller URI.

Daemon path:

PMIx_Setenv("PRTE_MCA_ess_base_nspace", dvm_nspace, true, &environ);
PMIx_Setenv("PRTE_MCA_ess_base_vpid", rank_str, true, &environ);
PMIx_Setenv("PRTE_MCA_ess_base_num_procs", ndaemons_str, true, &environ);
PMIx_Setenv("PRTE_MCA_prte_hnp_uri", ctrl_uri, true, &environ);   /* Step 4 */
PMIx_Setenv(port_param, port_str, true, &environ);   /* family-specific; see Step 5 */
*is_controller = false;

The ess/env component already wins selection for a daemon (PRTE_PROC_IS_DAEMON → priority 1) and its env_set_name() reads these three ess_base parameters into PRTE_PROC_MY_NAME and prte_process_info.num_daemons. No new ess component is needed.

In both paths PRTE_MCA_prte_keep_fqdn_hostnames is set from cfg.keep_fqdn (Step 6).

8.4.2.5. Step 4 — Synthesize the controller contact URI

A compute daemon must set prte_process_info.my_hnp_uri to a URI the RML can parse (prte_rml_parse_uris → set_addr). The two forms produced by prte_oob_base_get_addr(), one per address family, are:

<process-name>;tcp://<ipv4>:<port>:<if_mask>          # DVMIPVersion=4
<process-name>;tcp6://[<ipv6>]:<port>:<if_mask>       # DVMIPVersion=6

where <process-name> is the controller’s name (<ClusterName>-prte-dvm, rank 0) rendered by prte_util_convert_process_name_to_string(), and the transport tuple is the controller’s IP, the shared DVMPort, and an interface mask. Bootstrap:

1. Resolves cfg.ctrlhost to an address of the selected family (getaddrinfo with ai_family = AF_INET or AF_INET6 per cfg.ip_version).

2. Disambiguates a multi-homed host. When the name resolves to several addresses, the DVMNetworks CIDR entries select the one on the DVM interconnect (pmix_net_samenetwork). A host that resolves to more than one address with no CIDR to narrow it to exactly one is a hard error with a diagnostic naming the host (bootstrap-ambiguous-address / bootstrap-no-matching-address), rather than a silently-wrong interface. A single-homed host is unambiguous and needs no DVMNetworks entry.

3. Builds the process-name string for (dvm_nspace, 0).

4. Fills the mask field from cfg.dvm_netmask when the administrator supplied DVMNetmask; otherwise from the prefix of the DVMNetworks CIDR that selected the address; otherwise leaves it empty and relies on the parser tolerating an empty mask (below).

5. Assembles the URI in the form matching cfg.ip_version — tcp:// for IPv4, or tcp6://[...] (bracketed address, per RFC 3986) for IPv6 — and sets it as PRTE_MCA_prte_hnp_uri.

This synthesis is a pure function of (rank, host) — the port is the shared DVMPort and the name follows from the rank — so the same routine builds any peer’s URI, not just the controller’s. prte_ess_base_bootstrap_peer_uri exposes it: the controller URI is the rank-0 case, and a daemon in a deep radix tree uses it to reach a non-HNP parent (Step 7b).

The DVMNetmask key gives the mask field an explicit, administrator-controlled value when the DVMNetworks prefix is not the desired reachability mask. When neither is present the empty-mask fallback (below) applies.

Note

Empty-mask tolerance is still required as the fallback for when DVMNetmask is omitted. set_addr() in oob_base_stubs.c parses the third, if_mask, field of each transport tuple and uses it for reachability filtering. Make set_addr() treat a missing/empty mask field as “reachable” (rather than requiring the operator to always set DVMNetmask), and verify the change does not regress the normal launched path, where the mask is always present. This localized parser change is the primary implementation risk and should be prototyped first.

8.4.2.6. Step 5 — Apply the address family, listening port, and inter-node networks

Address family. DVMIPVersion (cfg.ip_version) chooses the family for all inter-node communication, and bootstrap resolves it into three things: the name of the static-port MCA parameter, the family enable/disable flags, and the URI form of Step 4. Because disable_ipv6_family defaults to true in the OOB, an IPv6-only DVM must positively enable it:

if (6 == cfg.ip_version) {
#if !PRTE_ENABLE_IPV6
    /* built without IPv6 — cannot honor DVMIPVersion=6 */
    pmix_show_help("help-prte-runtime.txt", "bootstrap-ipv6-unavailable",
                   true, prte_process_info.nodename);
    return PRTE_ERR_SILENT;   /* help already shown; match file convention */
#endif
    port_param = "PRTE_MCA_prte_static_ipv6_ports";
    PMIx_Setenv("PRTE_MCA_prte_disable_ipv6_family", "0", true, &environ);
    PMIx_Setenv("PRTE_MCA_prte_disable_ipv4_family", "1", true, &environ);
} else {
    port_param = "PRTE_MCA_prte_static_ipv4_ports";
    /* IPv4 is the OOB default; no family flags need forcing */
}

The #if !PRTE_ENABLE_IPV6 guard keeps the project’s #if FOO discipline and turns “configured for IPv6 on an IPv4-only build” into an explicit, diagnosed failure rather than a silent fall-through.

Listening port. The single DVMPort is applied uniformly through the existing static-port machinery: bootstrap sets port_param (the family value resolved above) to DVMPort on every process — controller and daemon alike (Step 3 code). The oob/tcp listener already consumes the static_ipvN_ports values; no listener change is needed. Because the port is well-known and shared across the DVM, any daemon can construct any peer’s contact tuple from its rank and node name — which is what makes the launcher-less URI synthesis in Step 4 possible.

Inter-node networks. DVMNetworks — the comma-delimited list of networks/interfaces the runtime should use for inter-node communication — is applied by setting PRTE_MCA_prte_if_include from cfg.dvm_networks. prte_if_include already accepts a comma-delimited list of interface names or CIDR subnets of either family (split_and_resolve in oob/tcp), so binding needs no code change; the key lets the administrator pin the runtime’s transport to specific networks from the same prte.conf (per the precedence rule, overriding any if_include in the MCA param file). When DVMNetworks is omitted the runtime’s default interface selection is unchanged. Its CIDR entries serve a second purpose in Step 4: disambiguating which resolved address a synthesized peer URI should target on a multi-homed host.

8.4.2.7. Step 6 — Wire the KeepFQDNHostnames key

The parser reads KeepFQDNHostnames into cfg.keep_fqdn (Step 1). Bootstrap seeds the existing MCA variable before prte_init so the choice made in prte.conf takes effect everywhere host names are matched or stored:

PMIx_Setenv("PRTE_MCA_prte_keep_fqdn_hostnames",
            cfg.keep_fqdn ? "1" : "0", true, &environ);

Bootstrap must also apply the same short-vs-FQDN normalization to its own node-matching in Step 2 (controller election and rank assignment), so its matching agrees with the runtime’s later behavior.

8.4.2.8. Step 7 — Startup retry with capped exponential backoff

Daemons boot independently; a compute daemon may try to reach the controller long before the controller’s listener is up, and there is no upper bound on how late the controller may arrive (a node in the boot order, a controller host that reboots). A bootstrap daemon must therefore never give up — it keeps trying to connect to the controller forever — but it must not busy-spin against a down controller either. The behavior is a capped exponential backoff: retry frequently at first, then after progressively longer delays, until the delay reaches a configured maximum, and then keep retrying at that maximum rate indefinitely.

The existing OOB reconnect path in oob_tcp_connection.c already reschedules a failed connect and already treats prte_max_recon_attempts < 0 as “infinite”, but its delay is fixed at prte_retry_delay seconds — there is no backoff and no cap. Two changes give us the desired curve:

1. Add a maximum-delay MCA parameter. Register prte_retry_max_delay (seconds) alongside prte_retry_delay and prte_max_recon_attempts in oob_tcp.c. It defaults to 0, which means “no backoff — use the fixed retry_delay”, so the launched path is unchanged.

2. Compute the delay as a function of the attempt count. In the reconnect block of oob_tcp_connection.c (the !connected path that today sets tv.tv_sec = prte_oob_base.retry_delay), when retry_max_delay exceeds retry_delay derive the delay from the existing peer->num_retries counter and cap it:

   /* base case (retry_max_delay == 0): fixed delay, unchanged behavior */
   unsigned secs = prte_oob_base.retry_delay;
   if (prte_oob_base.retry_max_delay > prte_oob_base.retry_delay) {
       /* exponential backoff: retry_delay, 2x, 4x, ... capped */
       uint64_t d = (uint64_t) prte_oob_base.retry_delay << peer->num_retries;
       if (d > (uint64_t) prte_oob_base.retry_max_delay) {
           d = prte_oob_base.retry_max_delay;
       }
       secs = (unsigned) d;
   }
   tv.tv_sec = secs;
   

   The << num_retries shift is guarded by the cap, so the large-shift overflow is harmless (any value past the cap is clamped to retry_max_delay). num_retries is already incremented on each retry and reset to 0 on a successful connect, so no new state is needed.

Bootstrap seeds the curve. prte_retry_delay defaults to 0, which disables retry entirely, so bootstrap must positively enable it. It sets three parameters before prte_init:

• prte_retry_delay → a short initial delay (e.g. 1 s) — bootstrap’s own default, set with overwrite=false so an operator MCA setting wins.

• prte_max_recon_attempts → -1 (never give up) — likewise overwrite=false.

• prte_retry_max_delay → the value of the DVMRetryMaxDelay config key (default 5 s). This one comes from prte.conf, so it is set with overwrite=true per the precedence rule (config file trumps the MCA param file).

With retry_delay=1 and retry_max_delay=5 the delay sequence is 1, 2, 4, 5, 5, 5, … seconds — frequent early attempts that settle onto a steady 5-second poll and continue until the controller answers.

Note

The backoff is a general OOB improvement, not a bootstrap-only code path: it is gated on retry_max_delay > retry_delay, and with the default retry_max_delay = 0 the launched path keeps its exact current fixed-delay behavior. Only bootstrap turns it on, via DVMRetryMaxDelay.

8.4.2.9. Step 7b — Radix wireup and ancestor healing

Left to the retry loop alone, every daemon would phone home directly to the controller, and the controller would have to service one connection per node. Bootstrap instead wires each daemon into the radix routing tree at boot so a daemon connects to its parent and the controller serves at most DVMRadix children. Two knobs, both set from prte.conf before prte_init:

• Radix. ess_base_bootstrap.c publishes PRTE_MCA_rml_base_radix from cfg.radix (overwrite=true — config trumps). Because the radix and the DVMNodes ordering are identical on every node, each daemon’s prte_rml_compute_routing_tree() derives the same tree and therefore the same parent (lifeline). The synthesized phone-home URI targets that parent’s rank/host/DVMPort rather than always rank 0.

• Connect-max-time. A new prte_connect_max_time OOB parameter (registered in oob_tcp.c, default 0 = forever) is published from cfg.connect_max_time. It bounds how long the connection state machine will retry a non-lifeline peer before giving up.

Healing reuses the lost-connection climb. The DVM already climbs the ancestor tree when a live parent is lost: lost_connection (in oob_tcp_component.c) calls prte_rml_route_lost(rank), which for a non-HNP parent runs prte_rml_repair_routing_tree() — promoting the daemon to its grandparent and returning PRTE_SUCCESS (→ COMM_FAILED), or returning PRTE_ERR_FATAL for the HNP (→ LIFELINE_LOST, die). The bootstrap startup race — a parent that never comes up — is the same problem one step earlier, so it reuses the same logic:

• When a connection attempt to a non-lifeline peer exceeds connect_max_time, oob_tcp_connection.c gives up and activates PRTE_PROC_STATE_FAILED_TO_CONNECT (it already does this on hard failure; the change is the time bound).

• failed_to_connect (in oob_tcp_component.c) is made to mirror lost_connection: route the peer through prte_rml_route_lost(rank) so a missing parent triggers the same grandparent promotion and the climb walks up the tree. Reaching the controller (rank 0) yields the HNP path, which is retried forever rather than fatal — the daemon simply keeps trying the controller per Step 7.

• The adopted parent’s URI is synthesized on demand. Promotion changes the lifeline to the grandparent, but only the original parent’s URI was synthesized at boot, so the send that re-establishes the lifeline routes to a peer whose contact info is unknown. oob_base_stubs.c, at the point where it would otherwise declare the message undeliverable, calls prte_ess_base_bootstrap_peer_uri(hop) in a bootstrapped DVM to synthesize that peer’s URI (Step 4) and connect. This is the general case of the boot-time parent synthesis and covers every ancestor the climb may reach.

The net effect: a daemon waits DVMConnectMaxTime for each successive ancestor and, in the worst case (only the controller ever boots), climbs to rank 0 and retries it forever. RELM re-drives the rollup over the repaired tree, so no reported-in state is lost across a heal.

8.4.2.10. Step 8 — prted.c branch and prte bootstrap removal

prte_ess_base_bootstrap() gains an out-parameter (or a prte_bootstrap_is_controller global) reporting the election result. src/tools/prted/prted.c (currently line 343, which unconditionally proceeds to prte_init(PRTE_PROC_DAEMON)) becomes:

bool is_controller = false;
ret = prte_ess_base_bootstrap(&is_controller);
if (PRTE_SUCCESS != ret) {
    return ret;
}
...
ret = prte_init(&argc, &argv,
                is_controller ? PRTE_PROC_MASTER : PRTE_PROC_DAEMON);

A self-promoted prted running as PRTE_PROC_MASTER selects the ess/hnp module and becomes a full DVM controller — functionally the same as prte. This realizes the spec’s decision that the controller is a self-promoted prted booted uniformly across the cluster.

Remove the duplicate entry point. prte.c also honors --bootstrap (setting prte_bootstrap_setup at line 486). With the self-promotion model this path is redundant for DVM formation, and to keep exactly one bootstrap story it is removed: the PRTE_CLI_BOOTSTRAP handling is deleted from prte.c, and the --bootstrap option is dropped from the prte personality in schizo_prte.c (leaving it on prted only). Bootstrap is thereafter reachable exactly one way — prted --bootstrap, booted uniformly on every node, with the controller self-promoting. The prte_bootstrap_setup global remains (it still gates the ras/bootstrap component on the controller), now set solely on the prted path.

8.4.2.11. Step 9 — Controller-side node pool (ras/bootstrap)

On the controller, ras/bootstrap’s allocate() builds the node pool from DVMNodes. It must assign each node the same vpid the daemon on that node computes for itself in Step 2, so the controller’s view of rank ↔ node agrees with reality:

• The controller’s own node is rank 0 (already placed by ess/hnp at prte_node_pool[0]).

• Each DVMNodes entry is placed at prte_node_pool[rank] using the Step 2 rank rule (skipping the controller entry if present).

The draft currently appends nodes without ranks; this step replaces that with rank-indexed insertion via the shared parser’s node list, reusing the canonical-ordering helper from Step 2 (factor it into prte_bootstrap.c so both the ess and ras sides call one implementation).

8.4.2.12. Step 10 — Apply the operational and logging keys

The draft parses DVMTempDir, SessionTmpDir, the log paths, and (newly, per Step 1) the four log-state booleans, then frees them with no effect. Wire each to its existing runtime setting before prte_init:

• DVMTempDir / SessionTmpDir → the session-directory base (prte_process_info.tmpdir_base / the top session dir), matching how the --tmpdir family is applied today.

• ControllerLogPath / PRTEDLogPath and the *LogJobState / *LogProcState toggles → the controller/daemon state-logging options described in PRRTE DVM Configuration.

Each key is applied on the side it governs (controller-only keys only when is_controller). These are independent of DVM formation and can land after the formation path (Steps 1–9) is working.

8.4.2.13. Step 11 — Update the example config file and the configurator tool

Two user-facing artifacts enumerate every configuration key and must be kept in lockstep with the parser (Step 1), or an administrator will generate a prte.conf the runtime no longer understands.

Example config file — src/etc/prte.conf ships with every key present but commented out. Update it to:

• collapse DVMControllerPort and PRTEDPort into the single #DVMPort=7817;

• add the new keys in the Bootstrap Options block — #DVMNetworks=, #DVMNetmask=, #DVMIPVersion=4, #DVMRadix=64, #KeepFQDNHostnames=false, #DVMRetryMaxDelay=5, and #DVMConnectMaxTime=30.

Configurator tool — docs/_templates/configurator.html is the Sphinx template (editable source, not a generated artifact) rendered as the configurator.html page referenced from PRRTE DVM Configuration. It is a self-contained HTML form whose displayfile() JavaScript assembles a prte.conf from the field values via get_field() / get_checkbox_value(). Update it to match the key set:

• Replace the controller_port (DVMControllerPort) and prted_port (PRTEDPort) inputs with a single DVMPort input (default 7817), and the corresponding two get_field() lines in displayfile() with one.

• Add inputs and displayfile() emission for DVMNetworks, DVMNetmask, DVMIPVersion (a 4/6 selector), DVMRadix (default 64), DVMRetryMaxDelay (default 5), and DVMConnectMaxTime (default 30), plus a KeepFQDNHostnames on/off switch (reusing the existing onoffswitch pattern and get_checkbox_value()).

• Reconcile the standing note that reads “Hostname values should not be specified as fully qualified domain names” with the new KeepFQDNHostnames option: the note holds only when KeepFQDNHostnames=false (the default), so reword it to say that host names must be given short-form unless KeepFQDNHostnames is enabled, in which case they must be fully qualified — matching the host-matching rule the runtime applies (Step 6).

Neither artifact affects DVM formation, but both are part of the deliverable: the documentation-update requirement for a user-visible change applies here. Do not edit the rendered copies under docs/_build/ or any installed .../html/ tree — those regenerate from these sources.

8.4.2.14. Summary of files changed

File	Change
src/util/prte_bootstrap.h / .c (new)	The shared parser: prte_bootstrap_config_t, prte_bootstrap_parse(), the DVMNodes expander, and the canonical rank-ordering helper (Steps 1, 2, 9).
src/util/Makefile.am	Build the new object files.
src/mca/ess/base/ess_base_bootstrap.c	Replace the inlined parser with a call to prte_bootstrap_parse(); add identity computation, controller election, the env-publishing of identity/URI/port/FQDN, and the is_controller out-parameter (Steps 2–7).
src/mca/ess/base/base.h	Update the prte_ess_base_bootstrap() prototype (out-parameter).
src/mca/ras/bootstrap/ras_boot.c	Replace the inlined parser with prte_bootstrap_parse(); assign rank-indexed nodes via the shared ordering helper (Step 9).
src/tools/prted/prted.c	Branch on the election result to init as PRTE_PROC_MASTER vs PRTE_PROC_DAEMON (Step 8).
src/prted/prte.c	Remove the PRTE_CLI_BOOTSTRAP handling — one bootstrap story (Step 8).
src/mca/schizo/prte/schizo_prte.c	Drop the --bootstrap option from the prte personality; keep it on prted (Step 8).
src/rml/oob/oob_base_stubs.c	Make set_addr() tolerate a missing/empty interface-mask field so a synthesized controller URI parses (Step 4) — pending the prototype in Open risks.
src/rml/oob/oob_tcp.c	Register the new prte_retry_max_delay MCA parameter (Step 7).
src/rml/oob/oob_tcp_connection.c	Compute the reconnect delay as a capped exponential backoff when retry_max_delay > retry_delay (Step 7).
src/util/proc_info.c (or the tmpdir path)	Apply DVMTempDir / SessionTmpDir (Step 10).
src/mca/schizo/prte/help-*.txt / help-prte-runtime.txt	New diagnostics for a node absent from DVMNodes (bootstrap-node-not-member) and for DVMIPVersion=6 on a build without IPv6 (bootstrap-ipv6-unavailable).
src/etc/prte.conf	Collapse the two port keys to DVMPort; add DVMNetworks, DVMNetmask, DVMIPVersion, KeepFQDNHostnames, DVMRetryMaxDelay (Step 11).
docs/_templates/configurator.html	Same key changes in the form + displayfile() JS; reconcile the FQDN note with KeepFQDNHostnames (Step 11).
docs/configuration.rst	Documented the consolidated DVMPort and the new DVMNetworks / DVMNetmask / DVMIPVersion / DVMRetryMaxDelay keys (already updated).

8.4.2.15. Open risks

• URI interface-mask (Step 4). The synthesized controller URI must survive set_addr(). When DVMNetmask is set the mask field is populated and the URI parses as-is; the residual risk is the empty-mask fallback used when it is omitted. Prototype the “tolerate empty mask” change first and confirm it does not alter reachability filtering on the normal launched path. This is the highest-risk item; everything else reuses proven wiring.

• Retry backoff (Step 7). Confirm the capped-backoff change is inert on the launched path when retry_max_delay == 0 (its default), that seeding the bootstrap defaults with overwrite=false honors an operator override, and that an infinite (max_recon_attempts = -1) retry against a never-arriving controller backs off to the cap rather than busy-spinning or overflowing the shift.

• Host matching consistency. Bootstrap’s Step 2 matching and the runtime’s later prte_check_host_is_local / prte_keep_fqdn_hostnames matching must agree; a mismatch would let a daemon elect itself correctly yet be placed at the wrong node index on the controller. Exercise with both short and FQDN configurations.

• IPv6-only clusters. DVMIPVersion=6 is handled in Steps 4–5 (family-specific port parameter, disable_ipv*_family flags, and the tcp6://[...] URI form), gated on a PRTE_ENABLE_IPV6 build. The residual verification is that a synthesized tcp6 URI round-trips through set_addr() (including the empty-mask fallback) exactly as the tcp4 form does, and that disabling the IPv4 family on an IPv6-only DVM does not disturb the loopback/self short-circuit paths. Dual-stack (both families active at once) is out of scope: DVMIPVersion selects exactly one.

8.4.2.16. Testing

There is no unit-test harness; validate by forming a DVM. The existing contrib/dockerswarm multi-node harness (used for elastic-mode testing) is the natural vehicle: pre-position an identical prte.conf in every container, boot prted --bootstrap on each, and confirm the controller elects itself, every compute daemon phones home and appears in the routing tree, and prun -n N hostname launches across the bootstrapped DVM. Test the boot-order-skew case by delaying the controller container’s start so the compute daemons must retry (Step 7).