Post-rebase corrections

The corrections were made to reconcile changes made in both the main
branch and in the current one. The following problems were addressed:

- both branches introduced changes to the Qmeta schema (up to version 10)
- a configuration of the worker's result delivery REST service changed in the main branch
- class move was made in the feature branch: qdisp::MessageStore -> qmeta::MessageStore

src/ccontrol/UserQueryQueries.cc

@@ -35,7 +35,7 @@
 // Qserv headers
 #include "css/CssAccess.h"
 #include "css/CssError.h"
-#include "qdisp/MessageStore.h"
+#include "qmeta/MessageStore.h"
 #include "qmeta/Exceptions.h"
 #include "qmeta/QMetaSelect.h"
 #include "query/FromList.h"
@@ -68,7 +68,7 @@ UserQueryQueries::UserQueryQueries(std::shared_ptr<query::SelectStmt> const& sta
         : _resultDbConn(resultDbConn),
           _qMetaSelect(qMetaSelect),
           _qMetaCzarId(qMetaCzarId),
-          _messageStore(std::make_shared<qdisp::MessageStore>()),
+          _messageStore(std::make_shared<qmeta::MessageStore>()),
           _resultTableName(::g_nextResultTableId(userQueryId)),
           _resultDb(resultDb) {
     // The SQL statement should be mostly OK alredy but we need to change

src/ccontrol/UserQueryQueries.h

@@ -89,7 +89,7 @@ class UserQueryQueries : public UserQuery {
     void discard() override;
 
     // Delegate objects
-    std::shared_ptr<qdisp::MessageStore> getMessageStore() override { return _messageStore; }
+    std::shared_ptr<qmeta::MessageStore> getMessageStore() override { return _messageStore; }
 
     /// @return Name of the result table for this query, can be empty
     std::string getResultTableName() const override { return _resultTableName; }
@@ -108,7 +108,7 @@ class UserQueryQueries : public UserQuery {
     std::shared_ptr<qmeta::QMetaSelect> _qMetaSelect;
     qmeta::CzarId const _qMetaCzarId;  ///< Czar ID in QMeta database
     QueryState _qState = UNKNOWN;
-    std::shared_ptr<qdisp::MessageStore> _messageStore;
+    std::shared_ptr<qmeta::MessageStore> _messageStore;
     std::string _resultTableName;
     std::string _query;  ///< query to execute on QMeta database
     std::string _orderBy;

src/qmeta/QMetaMysql.cc

@@ -50,7 +50,7 @@ using namespace std;
 namespace {
 
 // Current version of QMeta schema
-char const VERSION_STR[] = "10";
+char const VERSION_STR[] = "11";
 
 LOG_LOGGER _log = LOG_GET("lsst.qserv.qmeta.QMetaMysql");
 

src/qmeta/schema/migrate-10-to-11.sql

@@ -0,0 +1,13 @@
+CREATE TABLE IF NOT EXISTS `chunkMap` (
+  `worker` VARCHAR(256) NOT NULL COMMENT 'A unique identifier of a worker hosting the chunk replica',
+  `database` VARCHAR(256) NOT NULL COMMENT 'The name of a database',
+  `table` VARCHAR(256) NOT NULL COMMENT 'The name of a table',
+  `chunk` INT UNSIGNED NOT NULL COMMENT 'The number of a chunk',
+  `size` BIGINT UNSIGNED NOT NULL COMMENT 'The size of a chunk')
+ENGINE = InnoDB
+COMMENT = 'Chunk disposition across workers';
+
+CREATE TABLE IF NOT EXISTS `chunkMapStatus` (
+  `update_time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT 'The most recent update time of the map')
+ENGINE = InnoDB
+COMMENT = 'Satus info on the chunk map';

src/qmeta/schema/migrate-None-to-10.sql.jinja → src/qmeta/schema/migrate-None-to-11.sql.jinja

@@ -195,6 +195,28 @@ CREATE TABLE IF NOT EXISTS `QMessages` (
 ENGINE = InnoDB
 COMMENT = 'Table of messages generated during queries.';
 
+-- -----------------------------------------------------
+-- Table `chunkMap`
+-- -----------------------------------------------------
+
+CREATE TABLE IF NOT EXISTS `chunkMap` (
+  `worker` VARCHAR(256) NOT NULL COMMENT 'A unique identifier of a worker hosting the chunk replica',
+  `database` VARCHAR(256) NOT NULL COMMENT 'The name of a database',
+  `table` VARCHAR(256) NOT NULL COMMENT 'The name of a table',
+  `chunk` INT UNSIGNED NOT NULL COMMENT 'The number of a chunk',
+  `size` BIGINT UNSIGNED NOT NULL COMMENT 'The size of a chunk')
+ENGINE = InnoDB
+COMMENT = 'Chunk disposition across workers';
+
+-- -----------------------------------------------------
+-- Table `chunkMapStatus`
+-- -----------------------------------------------------
+
+CREATE TABLE IF NOT EXISTS `chunkMapStatus` (
+  `update_time` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT 'The most recent update time of the map')
+ENGINE = InnoDB
+COMMENT = 'Satus info on the chunk map';
+
 -- Update version on every schema change.
 -- Version 0 corresponds to initial QMeta release and it had no
 -- QMetadata table at all.
@@ -208,4 +230,5 @@ COMMENT = 'Table of messages generated during queries.';
 -- Version 8 replaced INT with BIGINT in the byte and row counter columns of QInfo.
 -- Version 9 removed the full-text index on the query text from QInfo.
 -- Version 10 redefined schema of the ProcessList tables.
-INSERT INTO `QMetadata` (`metakey`, `value`) VALUES ('version', '10');
+-- Version 11 added the worker-to-chunk map tables chunkMap and chunkMapStatus
+INSERT INTO `QMetadata` (`metakey`, `value`) VALUES ('version', '11');

src/wbase/Task.cc

@@ -76,8 +76,6 @@ size_t const MB_SIZE_BYTES = 1024 * 1024;
 
 namespace lsst::qserv::wbase {
 
-string const Task::_fqdn = util::get_current_host_fqdn();
-
 // Task::ChunkEqual functor
 bool Task::ChunkEqual::operator()(Task::Ptr const& x, Task::Ptr const& y) {
     if (!x || !y) {

src/wbase/UberJobData.cc

@@ -48,6 +48,8 @@
 using namespace std;
 using namespace nlohmann;
 
+namespace fs = boost::filesystem;
+
 namespace {
 
 LOG_LOGGER _log = LOG_GET("lsst.qserv.wbase.UberJobData");
@@ -180,35 +182,28 @@ void UberJobData::_queueUJResponse(http::Method method_, std::vector<std::string
     }
 }
 
-string UberJobData::buildUjResultFilePath(string const& resultsDirname) {
-    if (resultsDirname.empty()) return resultsDirname;
-    boost::filesystem::path path(resultsDirname);
+string UberJobData::_resultFileName() const {
     // UberJobs have multiple chunks which can each have different attempt numbers.
     // However, each CzarID + UberJobId should be unique as UberJobs are not retried.
-    path /= to_string(getCzarId()) + "-" + to_string(getQueryId()) + "-" + to_string(getUberJobId()) + "-0" +
-            ".proto";
-    return path.string();
+    return to_string(getCzarId()) + "-" + to_string(getQueryId()) + "-" + to_string(getUberJobId()) + "-0" +
+           ".proto";
 }
 
-string UberJobData::resultFilePath() {
-    auto const workerConfig = wconfig::WorkerConfig::instance();
-    string resultFilePath = buildUjResultFilePath(workerConfig->resultsDirname());
-    return resultFilePath;
+string UberJobData::resultFilePath() const {
+    string const resultsDirname = wconfig::WorkerConfig::instance()->resultsDirname();
+    if (resultsDirname.empty()) return resultsDirname;
+    return (fs::path(resultsDirname) / _resultFileName()).string();
 }
 
-std::string UberJobData::resultFileHttpUrl() {
+std::string UberJobData::resultFileHttpUrl() const {
     auto const workerConfig = wconfig::WorkerConfig::instance();
     auto const resultDeliveryProtocol = workerConfig->resultDeliveryProtocol();
-
-    string resFilePath = resultFilePath();
-    auto const fqdn = _foreman->getFqdn();
     if (resultDeliveryProtocol != wconfig::ConfigValResultDeliveryProtocol::HTTP) {
         throw runtime_error("wbase::Task::Task: unsupported results delivery protocol: " +
                             wconfig::ConfigValResultDeliveryProtocol::toString(resultDeliveryProtocol));
     }
     // TODO:UJ it seems like this should just be part of the FileChannelShared???
-    string resultFileHttpUrl = "http://" + fqdn + ":" + to_string(_resultsHttpPort) + resFilePath;
-    return resultFileHttpUrl;
+    return "http://" + _foreman->getFqdn() + ":" + to_string(_resultsHttpPort) + "/" + _resultFileName();
 }
 
 void UberJobData::cancelAllTasks() {

src/wbase/UberJobData.h

@@ -117,11 +117,10 @@ class UberJobData : public std::enable_shared_from_this<UberJobData> {
     /// that there is no limit to the number of rows sent back by the worker.
     /// Workers can only safely limit rows for queries that have the LIMIT clause without other related
     /// clauses like ORDER BY.
-    int getRowLimit() { return _rowLimit; }
+    int getRowLimit() const { return _rowLimit; }
 
-    std::string buildUjResultFilePath(std::string const& resultsDirname);
-    std::string resultFilePath();
-    std::string resultFileHttpUrl();
+    std::string resultFilePath() const;
+    std::string resultFileHttpUrl() const;
 
 private:
     UberJobData(UberJobId uberJobId, std::string const& czarName, qmeta::CzarId czarId, std::string czarHost,
@@ -130,6 +129,9 @@ class UberJobData : public std::enable_shared_from_this<UberJobData> {
                 std::string const& workerId, std::shared_ptr<wcontrol::Foreman> const& foreman,
                 std::string const& authKey, uint16_t resultsHttpPort);
 
+    /// Return the name of the file that will contain the results of the query.
+    std::string _resultFileName() const;
+
     /// Queue the response to be sent to the originating czar.
     void _queueUJResponse(http::Method method_, std::vector<std::string> const& headers_,
                           std::string const& url_, std::string const& requestContext_,