Examples with NoConnectionSlotsException org.zalando.nakadi.exceptions.NoConnectionSlotsException used on opensource projects

Example 1 with NoConnectionSlotsException

use of org.zalando.nakadi.exceptions.NoConnectionSlotsException in project nakadi by zalando.

the class EventStreamController method streamEvents.

@RequestMapping(value = "/event-types/{name}/events", method = RequestMethod.GET)
public StreamingResponseBody streamEvents(@PathVariable("name") final String eventTypeName, @Nullable @RequestParam(value = "batch_limit", required = false) final Integer batchLimit, @Nullable @RequestParam(value = "stream_limit", required = false) final Integer streamLimit, @Nullable @RequestParam(value = "batch_flush_timeout", required = false) final Integer batchTimeout, @Nullable @RequestParam(value = "stream_timeout", required = false) final Integer streamTimeout, @Nullable @RequestParam(value = "stream_keep_alive_limit", required = false) final Integer streamKeepAliveLimit, @Nullable @RequestHeader(name = "X-nakadi-cursors", required = false) final String cursorsStr, final HttpServletRequest request, final HttpServletResponse response, final Client client) {
    final String flowId = FlowIdUtils.peek();
    return outputStream -> {
        FlowIdUtils.push(flowId);
        if (blacklistService.isConsumptionBlocked(eventTypeName, client.getClientId())) {
            writeProblemResponse(response, outputStream, Problem.valueOf(Response.Status.FORBIDDEN, "Application or event type is blocked"));
            return;
        }
        final AtomicBoolean connectionReady = closedConnectionsCrutch.listenForConnectionClose(request);
        Counter consumerCounter = null;
        EventStream eventStream = null;
        List<ConnectionSlot> connectionSlots = ImmutableList.of();
        final AtomicBoolean needCheckAuthorization = new AtomicBoolean(false);
        LOG.info("[X-NAKADI-CURSORS] \"{}\" {}", eventTypeName, Optional.ofNullable(cursorsStr).orElse("-"));
        try (Closeable ignore = eventTypeChangeListener.registerListener(et -> needCheckAuthorization.set(true), Collections.singletonList(eventTypeName))) {
            final EventType eventType = eventTypeRepository.findByName(eventTypeName);
            authorizeStreamRead(eventTypeName);
            // validate parameters
            final EventStreamConfig streamConfig = EventStreamConfig.builder().withBatchLimit(batchLimit).withStreamLimit(streamLimit).withBatchTimeout(batchTimeout).withStreamTimeout(streamTimeout).withStreamKeepAliveLimit(streamKeepAliveLimit).withEtName(eventTypeName).withConsumingClient(client).withCursors(getStreamingStart(eventType, cursorsStr)).withMaxMemoryUsageBytes(maxMemoryUsageBytes).build();
            // acquire connection slots to limit the number of simultaneous connections from one client
            if (featureToggleService.isFeatureEnabled(LIMIT_CONSUMERS_NUMBER)) {
                final List<String> partitions = streamConfig.getCursors().stream().map(NakadiCursor::getPartition).collect(Collectors.toList());
                connectionSlots = consumerLimitingService.acquireConnectionSlots(client.getClientId(), eventTypeName, partitions);
            }
            consumerCounter = metricRegistry.counter(metricNameFor(eventTypeName, CONSUMERS_COUNT_METRIC_NAME));
            consumerCounter.inc();
            final String kafkaQuotaClientId = getKafkaQuotaClientId(eventTypeName, client);
            response.setStatus(HttpStatus.OK.value());
            response.setHeader("Warning", "299 - nakadi - the Low-level API is deprecated and will " + "be removed from a future release. Please consider migrating to the Subscriptions API.");
            response.setContentType("application/x-json-stream");
            final EventConsumer eventConsumer = timelineService.createEventConsumer(kafkaQuotaClientId, streamConfig.getCursors());
            final String bytesFlushedMetricName = MetricUtils.metricNameForLoLAStream(client.getClientId(), eventTypeName);
            final Meter bytesFlushedMeter = this.streamMetrics.meter(bytesFlushedMetricName);
            eventStream = eventStreamFactory.createEventStream(outputStream, eventConsumer, streamConfig, bytesFlushedMeter);
            // Flush status code to client
            outputStream.flush();
            eventStream.streamEvents(connectionReady, () -> {
                if (needCheckAuthorization.getAndSet(false)) {
                    authorizeStreamRead(eventTypeName);
                }
            });
        } catch (final UnparseableCursorException e) {
            LOG.debug("Incorrect syntax of X-nakadi-cursors header: {}. Respond with BAD_REQUEST.", e.getCursors(), e);
            writeProblemResponse(response, outputStream, BAD_REQUEST, e.getMessage());
        } catch (final NoSuchEventTypeException e) {
            writeProblemResponse(response, outputStream, NOT_FOUND, "topic not found");
        } catch (final NoConnectionSlotsException e) {
            LOG.debug("Connection creation failed due to exceeding max connection count");
            writeProblemResponse(response, outputStream, e.asProblem());
        } catch (final NakadiException e) {
            LOG.error("Error while trying to stream events.", e);
            writeProblemResponse(response, outputStream, e.asProblem());
        } catch (final InvalidCursorException e) {
            writeProblemResponse(response, outputStream, PRECONDITION_FAILED, e.getMessage());
        } catch (final AccessDeniedException e) {
            writeProblemResponse(response, outputStream, FORBIDDEN, e.explain());
        } catch (final Exception e) {
            LOG.error("Error while trying to stream events. Respond with INTERNAL_SERVER_ERROR.", e);
            writeProblemResponse(response, outputStream, INTERNAL_SERVER_ERROR, e.getMessage());
        } finally {
            connectionReady.set(false);
            consumerLimitingService.releaseConnectionSlots(connectionSlots);
            if (consumerCounter != null) {
                consumerCounter.dec();
            }
            if (eventStream != null) {
                eventStream.close();
            }
            try {
                outputStream.flush();
            } finally {
                outputStream.close();
            }
        }
    };
}

Example 2 with NoConnectionSlotsException

use of org.zalando.nakadi.exceptions.NoConnectionSlotsException in project nakadi by zalando.

the class ConsumerLimitingService method acquireConnectionSlots.

@SuppressWarnings("unchecked")
public List<ConnectionSlot> acquireConnectionSlots(final String client, final String eventType, final List<String> partitions) throws NoConnectionSlotsException, ServiceUnavailableException {
    final List<String> partitionsWithNoFreeSlots = getPartitionsWithNoFreeSlots(client, eventType, partitions);
    if (partitionsWithNoFreeSlots.size() == 0) {
        final List<ConnectionSlot> slots = new ArrayList<>();
        final String lockZkPath = ZKPaths.makePath(LOCKS_ZK_PATH, client + "|" + eventType);
        try {
            return runLocked(() -> {
                // we need to check it again when we are under lock
                final List<String> occupiedPartitions = getPartitionsWithNoFreeSlots(client, eventType, partitions);
                if (occupiedPartitions.size() > 0) {
                    throw generateNoConnectionSlotsException(eventType, occupiedPartitions, client);
                }
                for (final String partition : partitions) {
                    final ConnectionSlot connectionSlot = acquireConnectionSlot(client, eventType, partition);
                    slots.add(connectionSlot);
                }
                return slots;
            }, zkLockFactory.createLock(lockZkPath));
        } catch (final NoConnectionSlotsException e) {
            throw e;
        } catch (final Exception e) {
            // in a case of failure release slots for partitions that already acquired slots
            slots.forEach(this::releaseConnectionSlot);
            throw new ServiceUnavailableException("Error communicating with zookeeper", e);
        }
    } else {
        throw generateNoConnectionSlotsException(eventType, partitionsWithNoFreeSlots, client);
    }
}